Fundamentals of Lung Auscultation

Chest auscultation has long been considered a useful part of the physical examination, going back to the time of Hippocrates. However, it did not become a widespread practice until the invention of the stethoscope by René Laënnec in 1816, which made the practice convenient and hygienic.1 During the second half of the 20th century, technological advances in ultrasonography, radiographic computed tomography (CT), and magnetic resonance imaging shifted interest from lung auscultation to imaging studies, which can detect lung disease with an accuracy never previously imagined. However, modern computer-assisted techniques have also allowed precise recording and analysis of lung sounds, prompting the correlation of acoustic indexes with measures of lung mechanics. This innovative, though still little used, approach has improved our knowledge of acoustic mechanisms and increased the clinical usefulness of auscultation. In this review, we present an overview of lung auscultation in the light of modern concepts of lung acoustics

Ensino do exame respiratório: o que é história e o que é necessidade?

A semiologia é uma das técnicas mais utilizadas na prática médica há séculos. Ensinada por meio de roteiros sistematizados, estudantes de inúmeras escolas da área de saúde por todo o mundo aprendem as manobras semiológicas como fundamento na avaliação dos pacientes. No entanto, apesar de extremamente difundida, discute-se pouco sobre sua acurácia como manobra diagnóstica. Tendo este ponto em vista, este artigo aborda a precisão das diversas manobras semiológicas do exame físico do aparelho respiratório e a descrição comparativa do seu ensino em diferentes escolas médicas no mundo. Como resultados, tem-se valores de acurácia discordantes, o que pode ser justificado pela qualidade dos estudos ou pelas variáveis analisadas que diferem entre os estudos e propostas de padronização. Em conclusão, a semiologia é a base da avaliação médica, independentemente dos avanços e disponibilidade dos exames de imagens, e cada manobra deve ser ensinada com seu devido valor científico. Conhecer a aplicabilidade e individualizar a prática das etapas do exame respiratório pode ser um caminho possível de adequação aos tempos atuais, sem impor perdas de informações relevantes para o desenvolvimento do raciocínio clínico.Medical semiology has been one of the most common techniques used in medical practice for centuries. Health science students around the globe learn these techniques through a systematized model as a fundamental skill for patient evaluation. However, though being widespread, little is known about semiology’s true accuracy as a diagnostic maneuver. Knowing that, through a literature review, this paper evaluated the precision of the preconized procedures that are used as part of the exam of the respiratory system and the comparative description of its teaching in different medical schools around the world. As a result, disagreement between several papers was found, which can be justified by the poor quality of the studies and the different variables that were studied in each one. However, one thing is still clear:  respiratory physical examination continues to be essential in medical practice, independently of the recent advances and availability of imaging exams. Teaching each step should consider available scientific evidence. The knowledge of the applicability and practical individualization of the respiratory examination can be a possible way for the current times without missing relevant information for developing clinical reasoning

Models and Analysis of Vocal Emissions for Biomedical Applications

The International Workshop on Models and Analysis of Vocal Emissions for Biomedical Applications (MAVEBA) came into being in 1999 from the particularly felt need of sharing know-how, objectives and results between areas that until then seemed quite distinct such as bioengineering, medicine and singing. MAVEBA deals with all aspects concerning the study of the human voice with applications ranging from the neonate to the adult and elderly. Over the years the initial issues have grown and spread also in other aspects of research such as occupational voice disorders, neurology, rehabilitation, image and video analysis. MAVEBA takes place every two years always in Firenze, Italy. This edition celebrates twenty years of uninterrupted and succesfully research in the field of voice analysis

Expert System with an Embedded Imaging Module for Diagnosing Lung Diseases

Lung diseases are one of the major causes of suffering and death in the world. Improved survival rate could be obtained if the diseases can be detected at its early stage. Specialist doctors with the expertise and experience to interpret medical images and diagnose complex lung diseases are scarce. In this work, a rule-based expert system with an embedded imaging module is developed to assist the general physicians in hospitals and clinics to diagnose lung diseases whenever the services of specialist doctors are not available. The rule-based expert system contains a large knowledge base of data from various categories such as patient's personal and medical history, clinical symptoms, clinical test results and radiological information. An imaging module is integrated into the expert system for the enhancement of chest X-Ray images. The goal of this module is to enhance the chest X-Ray images so that it can provide details similar to more expensive methods such as MRl and CT scan. A new algorithm which is a modified morphological grayscale top hat transform is introduced to increase the visibility of lung nodules in chest X-Rays. Fuzzy inference technique is used to predict the probability of malignancy of the nodules. The output generated by the expert system was compared with the diagnosis made by the specialist doctors. The system is able to produce results\ud which are similar to the diagnosis made by the doctors and is acceptable by clinical standards

The problem of the stethoscope: an enquiry, experimental and philosophical, into the properties of this instrument and the physics of auscultation

My interest in Stethoscopy dates back to the time when I first entered the class of Clinical Medicine. I had previously, while on war service, been interested in the propagation of sound in sea water, and finding that acoustics played so important a part in the diagnosis of pulmonary and cardiac conditions, I naturally sought to understand both the nature of intrathoracic vibratory disturbances and the mechanism of their conveyance to the ear.In those early days two great difficulties confronted me. Firstly, the difficulty of recognising the various pulmonary signs even when directed what to listen for; secondly, the difficulty of following the explanations tendered for the mechanism of their propagation and production.By the time I had finished my classes the former had been partly overcome, the latter remained. And so, immediately after graduation I found myself engrossed in the literature of auscultation. The more I read the more I became impressed with the need for greater scientific precision, so many of the observations amounting to little more than mere impressions.As it seemed logical that we should first endeavour to understand the mechanism of our instruments, I was ultimately led to undertake the work of this thesis, not relying merely upon observations and impressions, but taking as my guide the concepts and propositions framed chiefly by those great master minds in sound and sound sensation, Lord Rayleigh and Helmholtz.It is submitted that the reasoning, mathematical demonstrations, and experiments of the thesis warrant the following conclusions.(1) That the apprliation of the exact nature of things with reference to the vibratory behaviour both of the stethoscope and of the tissues is a very complex problem.(2) That these articles demonstrate what actually is involved in the problem.(3) That the few problems treated in more detail, e.g. the subject of resonance point to the hopelessness of anything like an exact mathematical or physical interpretation of the behaviour of the instrument.(4) That there is a great need for exact physical concepts both as regards the behaviour of the stethoscope and the thoracic structures e.g. that we should drop the term conduction (or at least restrict it to its proper physical connotation) and try to visualise the stethoscope and its contained air, as well as the corporeal structures, as systems or bodies performing molar vibrations and not as media in which wave propagation takes place.(5) That owing to the variable relationship between sound sensation and the external physical disturbances to which they are due, and owing to the manner in which sound sensation can be modified by education and personal bias in virtue of the subjective phenomena of analysis and attention, the exact comparison of any two instruments cannot be effected; and having so far no experimental means of recording and measuring faint sounds it cannot be done by purely objective means.(6 ) That the phenomena of selective resonance especially as attributable to the behaviour of the stethoscope is hardly ever observed. That it is not to be ex^ pected, because in the first place, the majority of auscultation sounds cannot be supposed capable of representation by a periodic function, i.e. that they partake more of th6 character of noises, and in the second place, £he only frequency at which selective resonance might occur would be that corresponding to very close isochronism with the gravest natural tone of the air enclosed in the chest piece.(7) That what is usually designated selective resonance on the part of the instrument is not a magnification of a vibration emenating from the body surface, but that it is an adventitious element- a superimposed tonal mass of sound generated by the enclosed air being set in vibration by irregular disturbances as well as regular and that it is related only in intensity to the forcing vibrations.(8) That true bone conduction in stethoscopy even in the monaural pattern is largely a misnomer. That so called bone conduction is really the transmission of a vibratory motion to the apparatus of the middle ear by the meatus walls and hence that the subsequent path, as in normal hearing as via. the stapes and not as in true bone conduction by the vibration of the cochlear walls.That diaphragms cause a modification in the sound in virtue of their own intrinsic properties and do not merely serve the purpose of preventing the encroachment of the soft parts on the lumen of the chest piece.That in the binaural instrument with rubber tubes transmission by the column of air is alone important. That the vibrations of the column of air depends on the variation in pressure in the air in the chest piece» That the variation in pressure in the air in the chest piece is effected both by the vibrations of the body surface and by rapid variations in the configuration of the chest piece, and that the best idea of the behaviour of this mass of air is to be arrived at by combining the fundamental concepts on which the theory of resonators is framed with the theory of stream lines in the motion of fluids.That the guiding considerations on which a binaural stethoscope should be designed are these»Consideration should first be given to the acoustics of the instrument, secondly to the ease with which it can be used, thirdly to portability.The part in contact with the body surface should not be metal but a bad conductor of heat.The actual shape of the chest piece is not directly a matter of importance.The interposition of a diaphragm means further modification of the original physical disturbances.The larger the area of body surface covered the louder the sounds.The thinner and lightly and more highly elastic (in the physical sense) the walls of the chest piece and the smaller its inertia, fee greater will be the contribution to the variation in pressure in the air it encloses.The adventitious rumbling effeot of the air chamber should be eliminated either by making the chamber small or by breaking the apace up by perforated diaphragms.The exit from the chest piece should be placed where the energy of motion is greatest.The air chamber should be deep enough to allow the encroachment of the soft parts within the lumen without producing any appreciable dimin^ion in the energy of motion in the vicinity of the exit.Rubber conducting tubes are an accepted necessity because of their flexibility. Though flexible metal means louder signals.The ear pieces must fit exactly and without the slightest discomfort into the meatus and the normal to the exit should be in the direction of the meatus. This can be provided for by the proper curving of the head tubes and their union by a spring of suitable tension.finally that advance in stethoscopy depends upon the introduction of an accessory source of energy controlled to act as a relay probably through the medium of the oscillation valve

Towards using Cough for Respiratory Disease Diagnosis by leveraging Artificial Intelligence: A Survey

Cough acoustics contain multitudes of vital information about pathomorphological alterations in the respiratory system. Reliable and accurate detection of cough events by investigating the underlying cough latent features and disease diagnosis can play an indispensable role in revitalizing the healthcare practices. The recent application of Artificial Intelligence (AI) and advances of ubiquitous computing for respiratory disease prediction has created an auspicious trend and myriad of future possibilities in the medical domain. In particular, there is an expeditiously emerging trend of Machine learning (ML) and Deep Learning (DL)-based diagnostic algorithms exploiting cough signatures. The enormous body of literature on cough-based AI algorithms demonstrate that these models can play a significant role for detecting the onset of a specific respiratory disease. However, it is pertinent to collect the information from all relevant studies in an exhaustive manner for the medical experts and AI scientists to analyze the decisive role of AI/ML. This survey offers a comprehensive overview of the cough data-driven ML/DL detection and preliminary diagnosis frameworks, along with a detailed list of significant features. We investigate the mechanism that causes cough and the latent cough features of the respiratory modalities. We also analyze the customized cough monitoring application, and their AI-powered recognition algorithms. Challenges and prospective future research directions to develop practical, robust, and ubiquitous solutions are also discussed in detail.Comment: 30 pages, 12 figures, 9 table