Introduction  The study of the dynamic properties of vocal fold vibration is important for understanding the vocal production mechanism and the impact of organic and functional changes. The advent of high-speed videolaryngoscopy (HSV) has provided the possibility of seeing the real cycle of vocal fold vibration in detail through high sampling rate of successive frames and adequate spatial resolution. Objective  To describe the technique, advantages, and limitations of using HSV and digital videokymography in the diagnosis of vocal pathologies. Methods  We used HSV and digital videokymography to evaluate one normophonic individual and four patients with vocal fold pathologies (nodules, unilateral paralysis of the left vocal fold, intracordal cyst, and adductor spasmodic dysphonia). The vocal fold vibration parameters (glottic closure, vibrational symmetry, periodicity, mucosal wave, amplitude, and glottal cycle phases) were assessed. Results  Differences in the vocal vibration parameters were observed and correlated with the pathophysiology. Conclusion  HSV is the latest diagnostic tool in visual examination of vocal behavior and has considerable potential to refine our knowledge regarding the vocal fold vibration and voice production, as well as regarding the impact of pathologic conditions have on the mechanism of phonation.

Nas últimas décadas, a medicina tem sido cada vez mais permeada pelo conceito de medicina baseada em evidências, na qual a pesquisa clínica possui papel crucial no estabelecimento de diretrizes diagnósticas e terapêuticas. Com o avanço da pesquisa clínica, surgiu a preocupação e o entendimento que certos padrões éticos devam ser obedecidos quando o objeto de estudo é o ser humano. A pesquisa em seres humanos baseia-se nos princípios da autonomia, beneficência, não maleficência e justiça. A Resolução 196/96 do Conselho Nacional de Saúde incorpora à legislação brasileira tais princípios bioéticos consagrados. OBJETIVO: Discutir os principais aspectos éticos envolvidos na pesquisa em seres humanos. MATERIAL E MÉTODO: Análise crítica da Resolução 196/96 do CNS e literatura correlata. CONCLUSÃO: A Resolução 196/96 do Conselho Nacional de Saúde regulamenta a experimentação em seres humanos, no entanto necessita de discussões mais profundas no que diz respeito ao consentimento livre e esclarecido, ao uso de placebo, à participação de pessoas em situação de vulnerabilidade e à realização de pesquisas em países em desenvolvimento.

In the last decades, medical care has been increasingly permeated by the concept of evidence-based-medicine, in which clinical research plays a crucial role in establishing diagnostic and treatment. Following the improvements in clinical research, we have a growing concern and understanding that some ethical issues must be respected when the subjects are human beings. Research with human subjects relies on the principles of autonomy, beneficence, no maleficence and justice. Ordinance 196/96 from the National Health Board adds to the Brazilian legislation such renowned bioethical principles. AIM: Discuss the main ethical aspects involved in research with human subjects. MATERIALS AND METHODS: Critical analysis of Ordinance 196/96 and related literature. CONCLUSION: Ordinance 196/96 rules research with human subjects; nevertheless, it requires more in-depth discussions regarding the informed consent, use of placebo, research with vulnerable populations and research in developing countries.