Models and Analysis of Vocal Emissions for Biomedical Applications

The MAVEBA Workshop proceedings, held on a biannual basis, collect the scientific papers presented both as oral and poster contributions, during the conference. The main subjects are: development of theoretical and mechanical models as an aid to the study of main phonatory dysfunctions, as well as the biomedical engineering methods for the analysis of voice signals and images, as a support to clinical diagnosis and classification of vocal pathologies

Biosimulation of Vocal Fold Inflammation and Healing

Personalized, pre-emptive and predictive medicine is the capstone of contemporary medical care. The central aim of this dissertation is to address clinical challenges in prescribing personalized therapy to patients with acute phonotrauma. Inflammation and healing, which are innate tissue responses to mechanical stress/ trauma, are regulated by a complex dynamic system. A systems biology approach, which combines empirical, mathematical and computational tools, was taken to study the biological complexity of this dynamic system in vocal fold injury.Computational agent-based models (ABMs) were developed to quantitatively characterize multiple cellular and molecular interactions around inflammation and healing. The models allowed for tests of various hypothetical effects of motion-based treatments in individuals with acute phonotrauma. A phonotrauma ABM was calibrated and verified with empirical data of a panel of inflammatory mediators, obtained from laryngeal secretions in individuals following experimentally induced phonotrauma and a randomly assigned motion-based treatment. A supplementary ABM of surgically induced vocal fold trauma was developed and subsequently calibrated and verified with empirical data of inflammatory mediators and extracellular matrix substances from rat studies, for the purpose of gaining insight into the &ldquo net effect &rdquo of cellular and molecular responses at the tissue level.ABM simulations reproduced and predicted trajectories of inflammatory mediators and extracellular matrix as seen in empirical data of phonotrauma and surgical vocal fold trauma. The simulation results illustrated a spectrum of inflammatory responses to phonotrauma, surgical trauma and motion-based treatments. The results suggested that resonant voice exercise may optimize the combination of para- and anti-inflammatory responses to accelerate healing. Moreover, the ABMs suggested that hyaluronan fragments might be an early molecular index of tissue damage that is sensitive to varying stress levels - from relatively low phonatory stress to high surgical stress.We propose that this translational application of biosimulation can be used to quantitatively chart individual healing trajectories, test the effects of different treatment options and most importantly provide new understanding of laryngeal health and healing. By placing biology on a firm mathematical foundation, this line of research has potential to influence the contour of scientific thinking and clinical care of vocal fold injury

Models and analysis of vocal emissions for biomedical applications: 5th International Workshop: December 13-15, 2007, Firenze, Italy

The MAVEBA Workshop proceedings, held on a biannual basis, collect the scientific papers presented both as oral and poster contributions, during the conference. The main subjects are: development of theoretical and mechanical models as an aid to the study of main phonatory dysfunctions, as well as the biomedical engineering methods for the analysis of voice signals and images, as a support to clinical diagnosis and classification of vocal pathologies. The Workshop has the sponsorship of: Ente Cassa Risparmio di Firenze, COST Action 2103, Biomedical Signal Processing and Control Journal (Elsevier Eds.), IEEE Biomedical Engineering Soc. Special Issues of International Journals have been, and will be, published, collecting selected papers from the conference

Development of a biologically derived acellular construct for small intestine replacement

Introduction: Short bowel syndrome is characterised by a severe reduction in the amount of functional intestine available as an absorptive surface. Attempts to lengthen the intestine by interposition of artificial tubular scaffolds juxtaposed between healthy tissues have shown limited success. Transplantation is limited due to organ shortage. The most promising solution may be implantation of tissue-engineered small intestine using natural scaffold. Materials and Results: Using a completely novel approach, up to 30cm lengths of ileum with the attached vasculature were harvested from porcine donors. Separate intestinal and vascular loops were identified and de-cellularised using individually tailored detergent-enzymatic protocols. The resulting scaffold was compared to native tissue in terms of retention of cellular and nuclear remnants, as well as structural and functional proteins. Its biocompatibility was assessed by subcutaneous implantation of 1cm2 pieces into rat recipients. The remodeling fate of grafts was determined by time related changes in the ratio of sub-populations of residual macrophages. Its mechanical strength and ease of handling was evaluated by performing a left-sided nephrectomy in an unrelated pig model, followed by end-to-end anastomosis of the de-cellularised scaffolds’ mesenteric vasculature to the appropriate renal artery and vein. In the last stage, porcine organoid units were isolated and their yield estimated for future in vitro studies. Conclusions: It is possible to simultaneously de-cellularise two different tissues of varying cellular configuration and composition effectively and efficiently over a relatively short period of time. The two key features of the de-cellularised scaffold are that 1) the scaffold has in place the necessary architectural topography of small intestine (including mucosal villi) and molecular cues for optimum re-cellularisation and 2) the attached vascular tree provides an ideal conduit for re-cellularisation using either vascular committed endothelial or progenitor cells. Ultimately, this scaffold can be used for constructing long segments of bio-engineered intestine with the possibility of immediate blood supply and re-vascularisation

Progenitor cells in auricular cartilage demonstrate promising cartilage regenerative potential in 3D hydrogel culture

The reconstruction of auricular deformities is a very challenging surgical procedure that could benefit from a tissue engineering approach. Nevertheless, a major obstacle is presented by the acquisition of sufficient amounts of autologous cells to create a cartilage construct the size of the human ear. Extensively expanded chondrocytes are unable to retain their phenotype, while bone marrow-derived mesenchymal stromal cells (MSC) show endochondral terminal differentiation by formation of a calcified matrix. The identification of tissue-specific progenitor cells in auricular cartilage, which can be expanded to high numbers without loss of cartilage phenotype, has great prospects for cartilage regeneration of larger constructs. This study investigates the largely unexplored potential of auricular progenitor cells for cartilage tissue engineering in 3D hydrogels

EFFECTS OF VOCAL INTENSITY AND PHYSICAL ACTIVITY LEVELS ON PHONATORY AND RESPIRATORY FUNCTION

The vocal folds act as gatekeeper to the flow of air into and out of the lower airway. Another function of the vocal folds is that of oscillating sound source. To date, research has shown that under high respiratory drive (HRD) conditions voice is breathy, suggesting respiratory function will be favored over voice as physiologic needs increase. The problem is for physically active voice users, acoustic goals are relatively fixed. This study used a “physiology of activity” paradigm within action theory to investigate the extent to which phonatory and respiratory functions may be affected by systemically varying vocal and metabolic goals. Thirty-two English-speaking females, ages 18-35 years, who were vocally untrained and recreationally active, participated in the study. Participants produced sets of seven consonant-vowel syllables, at rest, using a pre-determined pitch at a comfortable loudness and in a loud voice. Following, participants walked on a treadmill to achieve low and high workloads at established speed and grade adjustments. The same speech task was repeated, using the same vocal intensities. Order of vocal and exercise intensities were counterbalanced. In terms of phonatory function, Rlaw increased significantly more from a baseline of spontaneous voice at rest during loud voice compared to spontaneous voice, mediated by an increase in Ps. Moreover, Rlaw decreased significantly more from baseline with an increase in workload, resulting in increases in metabolic variables. The decrease in Rlaw coincided with numerical increases in airflow. Voice production, as compared to breathing, reduced Ve, interfering with gas exchange. No differences existed for metabolic variables between voice conditions. This study reflected an attempt to understand the impact of goal-oriented behavior on phonatory and respiratory functions during HRD by manipulating acoustic and metabolic goals. Consistent with prior research, voice, as opposed to breathing, resulted in airflow limitation during HRD, reducing ventilation and CO2 clearance. Extreme respiratory perturbations lead to decreases in phonatory function to support metabolic needs. As predicted by action theory, loud voice appeared to favor phonatory function when acoustic goal was specified, at least in the short term. Conversely, spontaneous voice demonstrated deference to respiratory function when acoustic goals remained unspecified

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

Pattern Recognition

Pattern recognition is a very wide research field. It involves factors as diverse as sensors, feature extraction, pattern classification, decision fusion, applications and others. The signals processed are commonly one, two or three dimensional, the processing is done in real- time or takes hours and days, some systems look for one narrow object class, others search huge databases for entries with at least a small amount of similarity. No single person can claim expertise across the whole field, which develops rapidly, updates its paradigms and comprehends several philosophical approaches. This book reflects this diversity by presenting a selection of recent developments within the area of pattern recognition and related fields. It covers theoretical advances in classification and feature extraction as well as application-oriented works. Authors of these 25 works present and advocate recent achievements of their research related to the field of pattern recognition