Method for automatic detection of wheezing in lung sounds

The present report describes the development of a technique for automatic wheezing recognition in digitally recorded lung sounds. This method is based on the extraction and processing of spectral information from the respiratory cycle and the use of these data for user feedback and automatic recognition. The respiratory cycle is first pre-processed, in order to normalize its spectral information, and its spectrogram is then computed. After this procedure, the spectrogram image is processed by a two-dimensional convolution filter and a half-threshold in order to increase the contrast and isolate its highest amplitude components, respectively. Thus, in order to generate more compressed data to automatic recognition, the spectral projection from the processed spectrogram is computed and stored as an array. The higher magnitude values of the array and its respective spectral values are then located and used as inputs to a multi-layer perceptron artificial neural network, which results an automatic indication about the presence of wheezes. For validation of the methodology, lung sounds recorded from three different repositories were used. The results show that the proposed technique achieves 84.82% accuracy in the detection of wheezing for an isolated respiratory cycle and 92.86% accuracy for the detection of wheezes when detection is carried out using groups of respiratory cycles obtained from the same person. Also, the system presents the original recorded sound and the post-processed spectrogram image for the user to draw his own conclusions from the data.

Invasive aspergillosis in a user of inhaled cocaine: rhinosinusitis with bone and cartilage destruction

Aspergillosis is an infection caused by saprophytic fungi of the genus Aspergillus, which typically occurs in immunosuppressed individuals, but has also been reported in immunocompetent patients. The main routes of entry are the respiratory tract, skin, cornea, and ear, and the infection may be localized or disseminated by contiguity or vascular invasion. We report a severe case of rhinosinusitis with cutaneous involvement, caused by invasive aspergillosis, in an immunocompetent user of inhaled cocaine. Invasive aspergillosis related to cocaine abuse has not yet been reported in the literature. After itraconazole treatment and surgical debridement, complete clinical remission was achieved. Nasal reconstruction with a skin graft over a silicone prosthesis resulted in a satisfactory esthetic outcome.

Feedback como estratégia de aprendizado no ensino médico

Fornecer feedback aos alunos é um importante aspecto da aprendizagem e um papel essencial dos docentes. No contexto da educação médica clínica, feedback se refere às informações que descrevem o desempenho dos alunos em determinada situação ou atividade. A habilidade de dar e receber feedback melhora os resultados da aprendizagem, uma vez que fornece a base para a aprendizagem autodirecionada e para a reflexão crítica, auxilia os alunos a corrigirem seus erros, reforça comportamentos desejáveis e mostra como o aluno pode melhorar. Apesar da evidente falta de feedback durante o curso médico, os alunos desejam e valorizam essa ferramenta construtiva, considerando-a um aspecto importante do ensino de qualidade. O feedback eficaz deve ser: assertivo, respeitoso, descritivo, oportuno e específico. Docentes e alunos deveriam ser preparados para dar e receber feedback. Coordenadores e diretores deveriam reconhecer o papel do feedback como uma importante estratégia de ensino- aprendizagem na graduação.

Feedback de usuários como subsídio para avaliação do estudante de medicina

A avaliação é fundamental para o processo ensino-aprendizagem. Diferentes métodos de avaliação e diversos atores envolvidos na avaliação podem fornecer elementos distintos, que, somados, fornecem melhor compreensão sobre a efetividade do processo educacional em suas variadas dimensões. A avaliação de habilidades e atitudes de estudantes tem recebido grande atenção recentemente. O envolvimento de pacientes no processo pode ser contributivo, pois sua perspectiva acrescenta informações ímpares. O presente estudo avaliou a aquisição de competências e habilidades de estudantes de Medicina no internato de Obstetrícia, sob o ponto de vista de gestantes. As pacientes responderam a um questionário segundo escala de Likert, com itens de avaliação divididos em habilidades de comunicação, exame físico e profissionalismo. Os resultados mostraram boa avaliação dos estudantes em geral, o que atribuímos ao sentimento de gratidão das pacientes. Algumas questões com maiores frequências de respostas negativas, porém, apontam aspectos que merecem maior atenção da escola médica pelo impacto que podem trazer à prática profissional. A perspectiva de pacientes na avaliação do estudante de Medicina poderá balizar estratégias de feedback para qualificar a formação médica.

Neural regulation of the stress response: glucocorticoid feedback mechanisms

The mammalian stress response is an integrated physiological and psychological reaction to real or perceived adversity. Glucocorticoids are an important component of this response, acting to redistribute energy resources to both optimize survival in the face of challenge and to restore homeostasis after the immediate challenge has subsided. Release of glucocorticoids is mediated by the hypothalamo-pituitary-adrenal (HPA) axis, driven by a neural signal originating in the paraventricular nucleus (PVN). Stress levels of glucocorticoids bind to glucocorticoid receptors in multiple body compartments, including the brain, and consequently have wide-reaching actions. For this reason, glucocorticoids serve a vital function in negative feedback inhibition of their own secretion. Negative feedback inhibition is mediated by a diverse collection of mechanisms, including fast, non-genomic feedback at the level of the PVN, stress-shut-off at the level of the limbic system, and attenuation of ascending excitatory input through destabilization of mRNAs encoding neuropeptide drivers of the HPA axis. In addition, there is evidence that glucocorticoids participate in stress activation via feed-forward mechanisms at the level of the amygdala. Feedback deficits are associated with numerous disease states, underscoring the necessity for adequate control of glucocorticoid homeostasis. Thus, rather than having a single, defined feedback ‘switch’, control of the stress response requires a wide-reaching feedback ‘network’ that coordinates HPA activity to suit the overall needs of multiple body systems.