Smart Devices Are Poised to Revolutionize the Usefulness of Respiratory Sounds.

The association between breathing sounds and respiratory health or disease has been exceptionally useful in the practice of medicine since the advent of the stethoscope. Remote patient monitoring technology and artificial intelligence offer the potential to develop practical means of assessing respiratory function or dysfunction through continuous assessment of breathing sounds when patients are at home, at work, or even asleep. Automated reports such as cough counts or the percentage of the breathing cycles containing wheezes can be delivered to a practitioner via secure electronic means or returned to the clinical office at the first opportunity.

Inspiratory crackles-early and late-revisited: identifying COPD by crackle characteristics.

Background: The significance of pulmonary crackles, by their timing during inspiration, was described by Nath and Capel in 1974, with early crackles associated with bronchial obstruction and late crackles with restrictive defects. Crackles are also described as 'fine' or 'coarse'. We aimed to evaluate the usefulness of crackle characteristics in the diagnosis of chronic obstructive pulmonary disease (COPD).

Cystic fibrosis in Canadian Hutterites.

Background: The Hutterite Brethren are a communal group of Anabaptists who live in the Western regions of North America, predominantly in the Western Canadian provinces. Due to a founder effect, Hutterites have a high rate of cystic fibrosis (CF) with genotypes limited to only two CFTR mutations. One-third of Hutterite patients with CF are pancreatic sufficient.

Prevalence and clinical associations of wheezes and crackles in the general population: the Tromsø study.

Background: Wheezes and crackles are well-known signs of lung diseases, but can also be heard in apparently healthy adults. However, their prevalence in a general population has been sparsely described. The objective of this study was to determine the prevalence of wheezes and crackles in a large general adult population and explore associations with self-reported disease, smoking status and lung function.

Adventitious and Normal Lung Sounds in the General Population: Comparison of Standardized and Spontaneous Breathing.

Background: For clinical practice and research, it would be easier to auscultate lung sounds without simultaneously measuring air flow. This study evaluated whether the presence of adventitious lung sounds and the characteristics of normal lung sounds differ between spontaneous and standardized breathing in a general population.

Methods: A cross-sectional study was conducted with 116 subjects (53.

The scope of sleep problems in Canadian children and adolescents with obesity.

Objective: To determine the scope of sleep concerns, clinical features, and polysomnography (PSG) results and to identify factors that predict obstructive sleep apnea (OSA) in a cohort of children with obesity.

Methods: The study was a multicenter retrospective chart review. Data were collected from three pediatric sleep laboratories over a two year period for all children of age 8-16 years with a body mass index [BMI] ≥95th centile who were undergoing PSG.

International perception of lung sounds: a comparison of classification across some European borders.

Introduction: Lung auscultation is helpful in the diagnosis of lung and heart diseases; however, the diagnostic value of lung sounds may be questioned due to interobserver variation. This situation may also impair clinical research in this area to generate evidence-based knowledge about the role that chest auscultation has in a modern clinical setting. The recording and visual display of lung sounds is a method that is both repeatable and feasible to use in large samples, and the aim of this study was to evaluate interobserver agreement using this method.

The highs and lows of wheezing: A review of the most popular adventitious lung sound.

Wheezing is the most widely reported adventitious lung sound in the English language. It is recognized by health professionals as well as by lay people, although often with a different meaning. Wheezing is an indicator of airway obstruction and therefore of interest particularly for the assessment of young children and in other situations where objective documentation of lung function is not generally available.

Wheezes, crackles and rhonchi: simplifying description of lung sounds increases the agreement on their classification: a study of 12 physicians' classification of lung sounds from video recordings.

Background: The European Respiratory Society (ERS) lung sounds repository contains 20 audiovisual recordings of children and adults. The present study aimed at determining the interobserver variation in the classification of sounds into detailed and broader categories of crackles and wheezes.

Methods: Recordings from 10 children and 10 adults were classified into 10 predefined sounds by 12 observers, 6 paediatricians and 6 doctors for adult patients.

Towards the standardisation of lung sound nomenclature.

Auscultation of the lung remains an essential part of physical examination even though its limitations, particularly with regard to communicating subjective findings, are well recognised. The European Respiratory Society (ERS) Task Force on Respiratory Sounds was established to build a reference collection of audiovisual recordings of lung sounds that should aid in the standardisation of nomenclature. Five centres contributed recordings from paediatric and adult subjects.

Breath stacking in children with neuromuscular disorders.

Respiratory muscle weakness in neuromuscular disorders (NMD) can lead to shallow breathing and respiratory insufficiency over time. Children with NMD often cannot perform maneuvers to recruit lung volume. In adults, breath stacking with a mask and one-way valve can achieve significantly increased lung volumes.

Long-term management of asthma in First Nations and Inuit children: A knowledge translation tool based on Canadian paediatric asthma guidelines, intended for use by front-line health care professionals working in isolated communities.

Asthma is a serious health problem for First Nations and Inuit children. In children younger than one year of age, asthma needs to be distinguished from viral bronchiolitis, which is unusually common in Canadian Aboriginal children. In children younger than six years of age, the diagnosis depends on the presence of typical symptoms, the absence of atypical features and the documentation of response to therapy - particularly a rapid, transient response to bronchodilators.

Isolated central sleep apnea in type I Chiari malformation: improvement after surgery.

Sleep apnea is a rare but well-known clinical feature of disorders of the craniocervical junction. It may be obstructive or central in nature, and rarely presents without other neurological symptoms. We report the cases of two children, presenting with isolated central sleep apnea leading to a diagnosis of type I Chiari malformation.

Air-borne and tissue-borne sensitivities of bioacoustic sensors used on the skin surface.

Measurements of body sounds on the skin surface have been widely used in the medical field and continue to be a topic of current research, ranging from the diagnosis of respiratory and cardiovascular diseases to the monitoring of voice dosimetry. These measurements are typically made using light-weight accelerometers and/or air-coupled microphones attached to the skin. Although normally neglected, air-borne sounds generated by the subject or other sources of background noise can easily corrupt such recordings, which is particularly critical in the recording of voiced sounds on the skin surface.

Effect of body position on lung sounds in healthy young men.

Background: The effect of body position on the generation of abnormal respiratory sounds (eg, snoring and stridor) is well recognized. Postural effects on normal lung sounds have been studied in less detail but need to be clarified if respiratory acoustic measurements are to be used effectively in clinical practice.

Methods: Lung sounds and airflow were recorded in six healthy male subjects.

Diagnostic potential in state space parameters of lung sounds.

The goal of this study was to investigate state space parameters of the lung sounds of healthy subjects and subjects with symptoms of asthma under different respiratory conditions. Our main objective was to elucidate the diagnostic potential of these parameters, which included embedding dimension (m), time delay (tau) and Lyapunov exponents (lambda). Lung sounds were acquired over the right lower lobe from six healthy subjects, ages 10-26 years, and from eight children with symptoms of asthma recorded pre- and post-bronchial provocation via methacholine challenge (MCh) and post-bronchial dilation (BD).

Classification of lung sounds during bronchial provocation using waveform fractal dimensions.

Lung sounds (LS) of children after bronchoconstriction should differ from baseline LS in terms of amplitude and pattern characteristics. To test these hypotheses, time-domain and fractal based analyses have been applied to LS acquired from eight children ages 9-15 y pre- and post-methacholine challenge (MCh). Change in forced expiratory volume in 1 s after MCh ranged from -4% to -37%, with change proportional to severity of bronchoconstriction.

Design, construction, and evaluation of a bioacoustic transducer testing (BATT) system for respiratory sounds.

Many different transducers are employed for recording respiratory sounds including accelerometers and microphones in couplers. However, there is no standard lung sound transducer or any device to compare transducers so that measurements from different laboratories can be determined to be of physiologic origin rather than technical artifacts of the transducers. To address this problem, we designed and constructed a prototype of a device that can be used to compare accelerometers, microphones enclosed in couplers, and stethoscopes.

Comparison of lung sound transducers using a bioacoustic transducer testing system.

Sensors used for lung sound research are generally designed by the investigators or adapted from devices used in related fields. Their relative characteristics have never been defined. We employed an artificial chest wall with a viscoelastic surface and a white noise signal generator as a stable source of sound to compare the frequency response and pulse waveform reproduction of a selection of devices used for lung sound research.

Qualitative and quantitative evaluation of heart sound reduction from lung sound recordings.

Recursive least squares (RLS) adaptive noise cancellation (ANC) and wavelet transform (WT) ANC have been applied and compared for heart sound (HS) reduction from lung sounds (LS) recordings. Novel processes for quantitative and qualitative evaluation of any method for HS reduction from LS have also been proposed.

Detection of respiratory sounds at the external ear.

Several clinical and ambulatory settings necessitate respiratory monitoring without a mouthpiece or facemask. Several studies have demonstrated the utility of breathing sound measurements performed on the chest or neck to detect airflow. However, there are limitations to skin surface measurements, including susceptibility to external noise and transducer motion.

Modeling and measurement of flow effects on tracheal sounds.

The analysis of breathing sounds measured over the extrathoracic trachea offers a noninvasive technique to monitor obstructions of the respiratory tract. Essential to development of this technique is a quantitative understanding of how such tracheal sounds are related to the underlying tract anatomy, airflow, and disease-induced obstructions. In this study, the first dynamic acoustic model of the respiratory tract was developed that takes into consideration such factors as turbulent sound sources and varying glottal aperture.