Assessment of vocal cord nodules: A case study in speech processing by using Hilbert-Huang Transform

Vocal cord nodules represent a pathological condition for which the growth of unnatural masses on vocal folds affects the patients. Among other effects, changes in the vocal cords' overall mass and stiffness alter their vibratory behaviour, thus changing the vocal emission generated by them. This causes dysphonia, i.e. abnormalities in the patients' voice, which can be analysed and inspected via audio signals. However, the evaluation of voice condition through speech processing is not a trivial task, as standard methods based on the Fourier Transform, fail to fit the non-stationary nature of vocal signals. In this study, four audio tracks, provided by a volunteer patient, whose vocal fold nodules have been surgically removed, were analysed using a relatively new technique: the Hilbert-Huang Transform (HHT) via Empirical Mode Decomposition (EMD); specifically, by using the CEEMDAN (Complete Ensemble EMD with Adaptive Noise) algorithm. This method has been applied here to speech signals, which were recorded before removal surgery and during convalescence, to investigate specific trends. Possibilities offered by the HHT are exposed, but also some limitations of decomposing the signals into so-called intrinsic mode functions (IMFs) are highlighted. The results of these preliminary studies are intended to be a basis for the development of new viable alternatives to the softwares currently used for the analysis and evaluation of pathological voice

Аnalysis and anthropometric study of port placement in robotic rectal cancer surgery

Robotic surgery is an innovative, minimally invasive technique, which has already proved its advantages in the operative-technical field by providing ergonomics, three dimensional (3D) visualization of the operative field, more precise dissection in narrow spaces, etc. The additional time needed for docking of the console and collision (internal and external) between the robotic hands is a part of the specific difficulties related to this type of surgery. The aim of this study was to analyze the position of ports and their efficiency in robotic rectal surgery based on our initial experience with this type of surgery in the University Hospital of Pleven- Bulgaria as well as to seek for additional anatomical landmarks to improve the work process. The initial experience with robotic rectal resections for rectal cancer revealed that the recommended distance of 8 cm between the ports doesn`t provide sufficient efficacy. Additional topography anatomical landmarks are required for personalized preoperative planning of port positions and enhanced effectiveness of the robotic system in rectal cancer treatment. Further studies in this field are necessary

Laryngeal High-Speed Videoendoscopy: Rationale and Recommendation for Accurate and Consistent Terminology

Purpose The authors discuss the rationale behind the term laryngeal high-speed videoendoscopy to describe the application of high-speed endoscopic imaging techniques to the visualization of vocal fold vibration. Method Commentary on the advantages of using accurate and consistent terminology in the field of voice research is provided. Specific justification is described for each component of the term high-speed videoendoscopy , which is compared and contrasted with alternative terminologies in the literature. Results In addition to the ubiquitous high-speed descriptor, the term endoscopy is necessary to specify the appropriate imaging technology and distinguish among modalities such as ultrasound, magnetic resonance imaging, and nonendoscopic optical imaging. Furthermore, the term video critically indicates the electronic recording of a sequence of optical still images representing scenes in motion, in contrast to strobed images using high-speed photography and non-optical high-speed magnetic resonance imaging. High-speed videoendoscopy thus concisely describes the technology and can be appended by the desired anatomical nomenclature such as laryngeal . Conclusions Laryngeal high-speed videoendoscopy strikes a balance between conciseness and specificity when referring to the typical high-speed imaging method performed on human participants. Guidance for the creation of future terminology provides clarity and context for current and future experiments and the dissemination of results among researchers. </jats:sec

Analysis of Longitudinal Phase Differences in Vocal-Fold Vibration Using Synchronous High-Speed Videoendoscopy and Electroglottography

OBJECTIVE: This investigation used synchronous high-speed videoendoscopy (HSV) and electroglottography (EGG) to systematically study contact and separation behavior along the length of the vocal folds. DESIGN: Repeated measures. METHODS: Facilitated by EGG and digital kymograms derived at 20%, 35%, 50%, 65%, and 80% of the posteroanterior length of the vocal folds, the pattern of vocal-fold contact and separation was determined for 7 female and 7 male vocally healthy subjects while producing “breathy,” “comfortable,” and “pressed” phonations. RESULTS: The female subjects consistently used an anterior-to-posterior contact pattern and posterior-to-anterior separation pattern when producing a breathy or comfortable voice, with several employing a simultaneous pattern of contact and/or separation for pressed phonation. The male subjects showed more variable “zipperlike” separation patterns, but consistently used a simultaneous contact pattern for pressed voice that was also commonly used when producing comfortable phonation. CONCLUSIONS: Findings indicate longitudinal phase differences in vocal-fold vibration are both common and expected in vocally healthy speakers. The implications for vocal assessment, as well as for the use and interpretation of the EGG signal, are discussed