Efficient and Explainable Deep Neural Networks for Airway Symptom Detection in Support of Wearable Health Technology

Mobile health wearables are often embedded with small processors for signal acquisition and analysis. These embedded wearable systems are, however, limited with low available memory and computational power. Advances in machine learning, especially deep neural networks (DNNs), have been adopted for efficient and intelligent applications to overcome constrained computational environments. In this study, evolutionary optimized DNNs were analyzed to classify three common airway-related symptoms, namely coughs, throat clears and dry swallows. As opposed to typical microphone-acoustic signals, mechano-acoustic data signals, which did not contain identifiable speech information for better privacy protection, were acquired from laboratory-generated and publicly available datasets. The optimized DNNs had a low footprint of less than 150 kB and predicted airway symptoms of interests with 83.7% accuracy on unseen data. By performing explainable AI techniques, namely occlusion experiments and class activation maps, mel-frequency bands up to 8,000 Hz were found as the most important feature for the classification. We further found that DNN decisions were consistently relying on these specific features, fostering trust and transparency of proposed DNNs. Our proposed efficient and explainable DNN is expected to support edge computing on mechano-acoustic sensing wearables for remote, long-term monitoring of airway symptoms.

Influence of SARS-CoV-2 on airway mucus production: A review and proposed model

Coronavirus disease 2019 (COVID-19) is a worldwide pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) that has affected millions of lives. Individuals who survive severe COVID-19 can experience sustained respiratory symptoms that persist for months after initial infection. In other airway diseases, abnormal airway mucus contributes to sustained airway symptoms. However, the impact of SARS-CoV-2 on airway mucus has received limited attention. In the current review, we assess literature describing the impact of SARS-CoV-2 on airway pathophysiology with specific emphasis on mucus production. Accumulating evidence suggests that the 2 major secreted airway mucin glycoproteins, MUC5AC and MUC5B, are abnormal in some patients with COVID-19. Aberrations in MUC5AC or MUC5B in response to SARS-CoV-2 infection are likely due to inflammation, though the responsible mechanisms have yet to be determined. Thus, we also provide a proposed model highlighting mechanisms that can contribute to acute and sustained mucus abnormalities in SARS-CoV-2, with an emphasis on inflammatory cells and mediators, including mast cells and histamine. Last, we bring to light the challenges of studying abnormal mucus production in SARS-CoV-2 infections and discuss the strengths and limitations of model systems commonly used to study COVID-19. The evidence to date suggests that ferrets, nonhuman primates, and cats may have advantages over other models to investigate mucus in COVID-19.

Propanolol as a treatment for deep infantile hemangioma: case report

Background: Infantile hemangiomas (IH) are common neoplasms composed of proliferating endothelial cells. The duration and the growth rate are variable; some grow very poorly, while others grow rapidly and at an unpredictable rate. Despite the relative frequency of IH and the possible severity of complications, there are currently no uniform treatment guidelines. Although most are not worrisome, about 12% of IHs are significantly complex; propranolol has been adopted as a treatment. Objective: Report a clinical case of lactanate with hemangioma treated with propranolol. Case report: A healthy newborn is presented, with the presence of small telangiectasias in the right hemicneck without association with obstetric trauma; of a healthy 31-year-old mother; During its evolution at 3 months of age, the area covered with telangiectasias turned deep blue and the growth of a protrusion began, ultrasound and angioresonance, showed soft tissues of the posterior cervical space a lobulated mass of 9.1x4.1x4.9cm in its longitudinal and transverse diameter respectively, diagnosing it as a deep hemangioma; which was treated with propanolol. Discussion: Asymptomatic newborns with infantile neck hemangiomas are clinically controlled for the first six months of life, 60% of them develop life-threatening airway symptoms; the identification of the hemangioma was due to its rapid growth and not due to the alteration of surrounding structures that put the well-being of the infant at risk. Regarding the application of Propranolol, its administration was immediately after its identification, to avoid future complications. Conclusion: administration of propranolol systemically eliminates the characteristic color and reduces the size of the hemangioma.

Air Pollution and the Airways: Lessons from a Century of Human Urbanization

Since the industrial revolution, air pollution has become a major problem causing several health problems involving the airways as well as the cardiovascular, reproductive, or neurological system. According to the WHO, about 3.6 million deaths every year are related to inhalation of polluted air, specifically due to pulmonary diseases. Polluted air first encounters the airways, which are a major human defense mechanism to reduce the risk of this aggressor. Air pollution consists of a mixture of potentially harmful compounds such as particulate matter, ozone, carbon monoxide, volatile organic compounds, and heavy metals, each having its own effects on the human body. In the last decades, a lot of research investigating the underlying risks and effects of air pollution and/or its specific compounds on the airways, has been performed, involving both in vivo and in vitro experiments. The goal of this review is to give an overview of the recent data on the effects of air pollution on healthy and diseased airways or models of airway disease, such as asthma or chronic obstructive pulmonary disease. Therefore, we focused on studies involving pollution and airway symptoms and/or damage both in mice and humans.

Laryngeal Subsite Analysis of Granulomatosis With Polyangiitis (Wegener’s)

Objective To analyze specific intralaryngeal findings associated with granulomatosis with polyangiitis (GPA). Study Design Retrospective chart review. Setting Tertiary referral center. Methods A retrospective chart review was performed on all patients diagnosed with GPA who were evaluated at the laryngology division of Massachusetts Eye and Ear Infirmary between January 2006 and September 2019. Results Forty-four patients (14 male, 30 female) were evaluated for laryngeal pathology. The mean age at onset was 48 years. Nine patients (21%) were identified with only vocal fold disease, 11 (25%) with subglottic disease, and 8 (18%) with disease at the glottis and subglottis (transglottic). The remaining 16 patients (36%) had a normal airway upon examination although they presented with laryngeal symptoms. Patients with glottic disease had statistically significantly lower voice-related quality of life scores than patients with isolated subglottic stenosis. Conclusions Although laryngeal manifestations of GPA is often described as a subglottic disease presenting with respiratory symptoms, subsite analysis show that only 25% of patients had subglottic disease alone, with similar rates of glottic disease alone. Laryngeal subsites have different epithelial mucosa, function, and physiology, and understanding the specific sites of involvement will determine symptoms and enable better analysis of the underlying mechanisms of disease. Glottic disease is associated with a reduction in vocal fold motion and voice changes. Subglottic involvement presents more frequently with airway symptoms. Further research is necessary to better define the specific regions of laryngeal involvement in patients diagnosed with GPA.

Upper airway symptoms associate with the eosinophilic phenotype of COPD

BackgroundThere is growing evidence that upper airway symptoms coexist with lower airway symptoms in Chronic Obstructive Pulmonary Disease (COPD). Still, the prevalence and impact of upper airway disease on the nature and course of COPD remain unclear. We aimed to describe this in a cross-sectional study.MethodsWe examined a cohort of COPD patients with pulmonary function tests, induced sputum, blood eosinophils, atopy tests, CT of the paranasal sinuses. Lower airway symptoms were assessed using the COPD assessment test (CAT), and upper airway symptoms were assessed using the nasal subdomain of the 22-item Sino Nasal Outcome Test (SNOT22nasal). We recruited patients from five sites in Denmark and Sweden. We excluded patients with a history of asthma.FindingsIn total, 180 patients (female 55%, age 67 (±8) years, FEV1% 52.4 (±16.6), GOLD stage: A:18%, B:54%, C:3%, D:25%) were included in the study. Seventy-four patients (41%) reported high upper airway symptoms (high UAS defined as SNOT22nasal≥6) with a median score of 10 (IQR 8–13). Patients with high UAS reported higher CAT scores (17.4 (±7.5) versus 14.9 ±6.6, p<0.05) and displayed higher fractions of eosinophils in blood (median 3.0% (IQR 1.6–4.2%) versus 2.3% (IQR 1.4–3.1), p<0.05) and in induced sputum (median 1.8% (IQR 0.3–7.1%) versus median 0.5% (IQR 0–1.7%), p<0.05). No differences in atopy, CT findings or exacerbation rates were observed.ConclusionCOPD patients with upper airway disease showed increased evidence of eosinophilic disease and increased lower airway symptom burden.

Anaphylaxis: subjective symptom reports of patients with a special focus on “near-death” experiences

SummaryAlmost all anaphylactic reactions are associated with subjective symptoms, which are also referred to “prodromi”, and are often not taken seriously. In 100 patients categorized with different severity grades, subjective symptoms were investigated in a personal interview with free/open questions regarding subjective feelings and symptoms (duration 5–90 min). After the interview, the patients were asked to complete a questionnaire about the exact occurrence of the reaction. Special focus was given to near-death experiences in severe reactions. Patients described feelings of “elevation”, “looking at themselves from outside”, “tunnel experiences” and “bright light”. In the kinetics of the anaphylactic reaction, cutaneous symptoms were most often reported as the first or second symptom, while cardiovascular and airway symptoms were also reported as the 3rd, 4th or 5th symptom. In 37% of the patients with severe reactions, everyday life has changed since suffering the anaphylactic episode.

Occupational cold exposure is associated with increased reporting of airway symptoms

Objective To determine if exposure to cold environments, during work or leisure time, was associated with increased reporting of airway symptoms in the general population of northern Sweden. Methods Through a population-based postal survey responded to by 12627 subjects, ages 18–70, living in northern Sweden, the occurrence of airway symptoms was investigated. Cold exposure during work or leisure time was self-reported on numerical rating scales. Binary logistic regression was used to determine the statistical association between cold exposure and airway symptoms. Results For currently working subjects (N = 8740), reporting any occupational cold exposure was associated to wheeze (OR 1.3; 95% CI 1.1–1.4); chronic cough (OR 1.2; 95% CI 1.1–1.4); and productive cough (OR 1.3; 95% CI 1.1–1.4), after adjusting for gender, age, body mass index, daily smoking, asthma, and chronic obstructive pulmonary disease. Leisure-time cold exposure was not significantly associated to reporting airway symptoms. Conclusions Occupational cold exposure was an independent predictor of airway symptoms in northern Sweden. Therefore, a structured risk assessment regarding cold exposure could be considered for inclusion in the Swedish workplace legislation.

Late Central Airway Toxicity after High-Dose Radiotherapy: Clinical Outcomes and a Proposed Bronchoscopic Classification

The study’s purpose was to identify the bronchoscopic patterns of central airway toxicity following high-dose radiotherapy or chemoradiotherapy, and to look at the consequences of these findings. Our institutional bronchoscopy database was accessed to identify main patterns of airway toxicity observed in a seven-year period. A total of 70 patients were identified with central airway toxicity, and the findings of bronchoscopy were used to derive a classification system. Patient characteristics, time from radiotherapy to toxicity, follow-up and survival were retrospectively analyzed. Results: The main bronchoscopic patterns of airway toxicity were vascular changes (telangiectasia, loss of vascularity, necrosis) and stenosis of the lumen (moderate, severe). Indications for bronchoscopy were airway symptoms (n = 28), assessment post-CRT/surgery (n = 12), (suspected) recurrence (n = 21) or assessment of radiological findings (n = 9). Stenosis was revealed by bronchoscopy at a median time of 10.0 months (IQR: 4–23.5) after radiotherapy and subsequent follow-up after identification was 23 months (IQR: 1.5–55). The corresponding findings for vascular changes were 29 months (IQR: 10.5–48.5), and follow-up after identification was nine months (IQR: 2.5–19.5). There was a statistically significant difference in survival rates between patients with necrosis and telangiectasia (p = 0.002) and loss of vascularity (p = 0.001). Eight out of 10 deceased patients with telangiectasia died of other causes and 4/8 patients with necrosis died of other causes. We identified two main patterns of central airway toxicity visualized with bronchoscopy after high-dose radiotherapy or chemoradiotherapy, and propose a bronchoscopic classification system based on these findings. Preliminary analysis suggests that the pattern and severity of radiation damage might be of prognostic value. Prospective data are required to confirm our findings.