Foetal heart rate recording: analysis and comparison of different methodologies

Monitoring foetal health is a very important task in clinical practice to appropriately plan pregnancy management and delivery. In the third trimester of pregnancy, ultrasound cardiotocography is the most employed diagnostic technique: foetal heart rate and uterine contractions signals are simultaneously recorded and analysed in order to ascertain foetal health. Because ultrasound cardiotocography interpretation still lacks of complete reliability, new parameters and methods of interpretation, or alternative methodologies, are necessary to further support physicians’ decisions. To this aim, in this thesis, foetal phonocardiography and electrocardiography are considered as different techniques. Further, variability of foetal heart rate is thoroughly studied. Frequency components and their modifications can be analysed by applying a time-frequency approach, for a distinct understanding of the spectral components and their change over time related to foetal reactions to internal and external stimuli (such as uterine contractions). Such modifications of the power spectrum can be a sign of autonomic nervous system reactions and therefore represent additional, objective information about foetal reactivity and health. However, some limits of ultrasonic cardiotocography still remain, such as in long-term foetal surveillance, which is often recommendable mainly in risky pregnancies. In these cases, the fully non-invasive acoustic recording, foetal phonocardiography, through maternal abdomen, represents a valuable alternative to the ultrasonic cardiotocography. Unfortunately, the so recorded foetal heart sound signal is heavily loaded by noise, thus the determination of the foetal heart rate raises serious signal processing issues. A new algorithm for foetal heart rate estimation from foetal phonocardiographic recordings is presented in this thesis. Different filtering and enhancement techniques, to enhance the first foetal heart sounds, were applied, so that different signal processing techniques were implemented, evaluated and compared, by identifying the strategy characterized on average by the best results. In particular, phonocardiographic signals were recorded simultaneously to ultrasonic cardiotocographic signals in order to compare the two foetal heart rate series (the one estimated by the developed algorithm and the other provided by cardiotocographic device). The algorithm performances were tested on phonocardiographic signals recorded on pregnant women, showing reliable foetal heart rate signals, very close to the ultrasound cardiotocographic recordings, considered as reference. The algorithm was also tested by using a foetal phonocardiographic recording simulator developed and presented in this research thesis. The target was to provide a software for simulating recordings relative to different foetal conditions and recordings situations and to use it as a test tool for comparing and assessing different foetal heart rate extraction algorithms. Since there are few studies about foetal heart sounds time characteristics and frequency content and the available literature is poor and not rigorous in this area, a data collection pilot study was also conducted with the purpose of specifically characterising both foetal and maternal heart sounds. Finally, in this thesis, the use of foetal phonocardiographic and electrocardiographic methodology and their combination, are presented in order to detect foetal heart rate and other functioning anomalies. The developed methodologies, suitable for longer-term assessment, were able to detect heart beat events correctly, such as first and second heart sounds and QRS waves. The detection of such events provides reliable measures of foetal heart rate, potentially information about measurement of the systolic time intervals and foetus circulatory impedance.

Neurolinguistic analysis: aspects of language and speech deviations in Palestinian Arabic aphasics

The characteristics of aphasics’ speech in various languages have been the core of numerous studies, but Arabic in general, and Palestinian Arabic in particular, is still a virgin field in this respect. However, it is of vital importance to have a clear picture of the specific aspects of Palestinian Arabic that might be affected in the speech of aphasics in order to establish screening, diagnosis and therapy programs based on a clinical linguistic database. Hence the central questions of this study are what are the main neurolinguistic features of the Palestinian aphasics’ speech at the phonetic-acoustic level and to what extent are the results similar or not to those obtained from other languages. In general, this study is a survey of the most prominent features of Palestinian Broca’s aphasics’ speech. The main acoustic parameters of vowels and consonants are analysed such as vowel duration, formant frequency, Voice Onset Time (VOT), intensity and frication duration. The deviant patterns among the Broca’s aphasics are displayed and compared with those of normal speakers. The nature of deficit, whether phonetic or phonological, is also discussed. Moreover, the coarticulatory characteristics and some prosodic patterns of Broca’s aphasics are addressed. Samples were collected from six Broca’s aphasics from the same local region. The acoustic analysis conducted on a range of consonant and vowel parameters displayed differences between the speech patterns of Broca’s aphasics and normal speakers. For example, impairments in voicing contrast between the voiced and voiceless stops were found in Broca’s aphasics. This feature does not exist for the fricatives produced by the Palestinian Broca’s aphasics and hence deviates from data obtained for aphasics’ speech from other languages. The Palestinian Broca’s aphasics displayed particular problems with the emphatic sounds. They exhibited deviant coarticulation patterns, another feature that is inconsistent with data obtained from studies from other languages. However, several other findings are in accordance with those reported from various other languages such as impairments in the VOT. The results are in accordance with the suggestions that speech production deficits in Broca’s aphasics are not related to phoneme selection but rather to articulatory implementation and some speech output impairments are related to timing and planning deficits.

Studi sull'immaginario musicale in Euripide

La dissertazione è suddivisa in due capitoli più tre appendici. Nel I capitolo, Musica e dolore, si indagano i casi di metamusicalità in riferimento al dolore, che si intensificano in Euripide: si nota lo sviluppo di una riflessione sul ruolo della mousike rispetto al dolore, espressa attraverso un lessico medico e musicale. Si dimostra che in Euripide si pone il problema di quale scopo abbia la musica, se sia utile, e in quale forma lo sia. Nella prima produzione si teorizza una mousa del lamento come dolce o terapeutica per chi soffre. Molti personaggi, però, mostrano sfiducia nel potere curativo del lamento. Nell’ultima produzione si intensificano gli interrogativi sulla performance del canto, che si connotano come casi metamusicali e metateatrali. Nell’Elena, nell’Ipsipile e nelle Baccanti, E. sembra proporre una terapia ‘omeopatica’ del dolore attraverso la musica orgiastico-dionisiaca. Nel II capitolo, Natura e musica, si sceglie l’Ifigenia Taurica come esempio di mimetismo orchestico-musicale fondato – oltre che su casi di autoreferenzialità – su un immaginario naturale che, ‘facendo musica’, contribuisce all’espressività della choreia e della musica in scena. Si ipotizza inoltre un accompagnamento musicale mimetico rispetto ai suoni della natura e movimenti di danza lineari accanto a formazioni circolari, che sembrano richiamare la ‘doppia natura’ del ditirambo. L’Appendice I, Gli aggettivi poetici ξουθός e ξουθόπτερος: il loro significato e la loro potenzialità allusiva, affronta un caso particolare e problematico di ‘mimetismo lessicale’, innescato dal termine ξουθός e dal composto euripideo ξουθόπτερος. Si dimostra che l’aggettivo indica originariamente un movimento vibratorio, ma sviluppa anche un senso sonoro, ed è quindi un termine evocativo rispetto alla performance. Nell’Appendice II, Il lessico musicale in Euripide, è raccolto il lessico euripideo coreutico-musicale. Nell’Appendice III, La mousike nei drammi euripidei, sono raccolti i riferimenti alla mousike in ogni dramma.

Mündliche Literatur in Amadou Hampaté Bâ’s Roman "Das seltsame Schicksal des Wangrin" /// Arbeitspapiere / Institut für Ethnologie und Afrikastudien ; 90

Amadou Hampaté Bâ legte mit „Das seltsame Schicksal des Wangrin“ einen vielstimmigen Roman vor, dessen Ästhetik entscheidend von der Einarbeitung und Inszenierung von Mündlicher Literatur bestimmt ist. In meinem Aufsatz gehe ich zum einen der Frage nach, inwieweit es Bâ unternimmt, den sinnlichen Reichtum Mündlicher Literatur, also entsprechende Sounds, Gestik, Mimik, Proxemik, musikalische Begleitung, in den einen graphischen Kommunikationskanal, in Schrift zu überführen, und zum anderen, inwiefern er die sprachlichen Anteile Mündlicher Literatur in das Romanganze hineinwebt, inwiefern er Verbindungen zwischen den Oraturen und den im Roman aufgerufenen sozialen Situationen herstellt. Im Zentrum der Untersuchung steht ein bestimmter Vortrag. Der Romanheld Wangrin lässt sich vor dem Haus der Mutter der von ihm umworbenen Rammaye Bira durch seinen Griot preisen, wirbt solcherart um die junge Frau. Herman Meyers Konzept der epischen Integration aufgreifend, lege ich dar, inwiefern diese eine Performanzsituation mit anderen Stellen, an denen im Roman Mündliche Literatur inszeniert wird, korrespondiert, um dadurch zu generelleren Aussagen über die Verfahrensweise Bâ’s hinsichtlich der Aufnahme von Mündlicher Literatur zu gelangen. Am Anfang des Aufsatzes fasse ich Charakteristika Mündlicher Literatur zusammen und problematisiere deren Überführung in den schriftlichen Modus.

Progettazione e sviluppo di un prototipo di dispositivo wearable per il monitoraggio dell'attivita elettro-meccanica del cuore

Il presente lavoro di tesi è finalizzato allo sviluppo di un dispositivo indossabile, e minimamente invasivo, in grado di registrare in maniera continua segnali legati all’attività elettromeccanica del muscolo cardiaco, al fine di rilevare eventuali anomalie cardiache. In tal senso il sistema non si limita alla sola acquisizione di un segnale ECG, ma è in grado di rilevare anche i toni cardiaci, ovvero le vibrazioni generate dalla chiusura delle valvole cardiache, la cui ampiezza è espressione della forza contrattile (funzione meccanica) del cuore. Il presente lavoro di tesi ha riguardato sia la progettazione che la realizzazione di un prototipo di tale dispositivo ed è stato svolto presso il laboratorio di Bioingegneria del Dipartimento di Medicina Specialistica Diagnostica e Sperimentale dell’Università di Bologna, sito presso l’Azienda Ospedaliero-Universitaria Policlinico Sant’Orsola-Malpighi. Il sistema finale consiste in un dispositivo applicabile al torace che, attraverso una serie di sensori, è in grado di rilevare dati legati alla meccanica del cuore (toni cardiaci), dati elettrici cardiaci (ECG) e dati accelerometrici di attività fisica. Nello specifico, il sensing dei toni cardiaci avviene attraverso un accelerometro in grado di misurare le vibrazioni trasmesse al torace. I tracciati, raccolti con l’ausilio di una piattaforma Arduino, vengono inviati, tramite tecnologia Bluetooth, ad un PC che, attraverso un applicativo software sviluppato in LabVIEW™, ne effettua l’analisi, il salvataggio e l’elaborazione in real-time, permettendo un monitoraggio wireless ed in tempo reale dello stato del paziente.

Nuovi suoni di balenottera comune (Balaenoptera physalus) nel Mediterraneo occidentale

Fin whale (Balaenoptera physalus) is the only misticeto commonly observed in the Mediterranean. The males emit sounds, classic pulse products in sequences called songs, at 20Hz for sexual purposes: sounds are produced during the spring for migration to the Tirreno-Ligurian-Provençal basin, the summer feeding area, and during the autumn, when there is a migration to the south to meet the winter breeding season. This area in the Mediterranean sea is unknown. The east coast of the Iberian Peninsula is a migration area. The study was conducted by analyzing through Adobe Audition 3.0 and XBAT softwares files audio of 30 minutes recorded in 2006, in 2011 and 2012 at the level of the Columbretes Islands, in the western Mediterranean sea, using two hearing aids: the MARU, used in 2006 and the EAR, used in 2011 and 2012. From the analysis have emerged that, in addition to songs with pulses of 20 Hz, there are new sounds of fin whale never previously recognized: the VFPs (Variable Frequency Pulses), higher-frequency pulses emitted, between 50 and 120Hz and the ramps, a set of 7-8 pulses, pertaining to a particular song, of increasing frequency. Further studies are needed to understand the importance of these new sounds.

Heart valve sound of various mechanical composite grafts, and the impact on patients' quality of life

The closing sounds of mechanical heart valves can be disturbing for patients and their closest relatives. Although some investigations into mechanical heart valve sounds have been performed, the particularities of the valve sound when it is attached to a vascular prosthesis to replace the aortic root and the ascending aorta has not been studied to date. The study aim was to compare the closing sounds of three various mechanical composite graft prostheses, and to analyze the impact of such sounds on the patients' quality of life.

Benefits of low-frequency attenuation of baha® in single-sided sensorineural deafness

To investigate the effect of low-frequency attenuation of Bone-Anchored Hearing Aids (Bahas) in users with single-sided sensorineural deafness (SSD). The underlying notion is that low-frequency sounds up to approximately 1500 Hz reach the contralateral ear without significant attenuation and that Bahas tend to show more distortion at lower frequencies. Furthermore, to transmit low frequencies, higher moving masses are needed when compared with high frequencies.

Musical Training Induces Functional Plasticity in Human Hippocampus

Training can change the functional and structural organization of the brain, and animal models demonstrate that the hippocampus formation is particularly susceptible to training-related neuroplasticity. In humans, however, direct evidence for functional plasticity of the adult hippocampus induced by training is still missing. Here, we used musicians' brains as a model to test for plastic capabilities of the adult human hippocampus. By using functional magnetic resonance imaging optimized for the investigation of auditory processing, we examined brain responses induced by temporal novelty in otherwise isochronous sound patterns in musicians and musical laypersons, since the hippocampus has been suggested previously to be crucially involved in various forms of novelty detection. In the first cross-sectional experiment, we identified enhanced neural responses to temporal novelty in the anterior left hippocampus of professional musicians, pointing to expertise-related differences in hippocampal processing. In the second experiment, we evaluated neural responses to acoustic temporal novelty in a longitudinal approach to disentangle training-related changes from predispositional factors. For this purpose, we examined an independent sample of music academy students before and after two semesters of intensive aural skills training. After this training period, hippocampal responses to temporal novelty in sounds were enhanced in musical students, and statistical interaction analysis of brain activity changes over time suggests training rather than predisposition effects. Thus, our results provide direct evidence for functional changes of the adult hippocampus in humans related to musical training.

Mental reversal of imagined melodies: A role for the posterior parietal cortex

Two fMRI experiments explored the neural substrates of a musical imagery task that required manipulation of the imagined sounds: temporal reversal of a melody. Musicians were presented with the first few notes of a familiar tune (Experiment 1) or its title (Experiment 2), followed by a string of notes that was either an exact or an inexact reversal. The task was to judge whether the second string was correct or not by mentally reversing all its notes, thus requiring both maintenance and manipulation of the represented string. Both experiments showed considerable activation of the superior parietal lobe (intraparietal sulcus) during the reversal process. Ventrolateral and dorsolateral frontal cortices were also activated, consistent with the memory load required during the task. We also found weaker evidence for some activation of right auditory cortex in both studies, congruent with results from previous simpler music imagery tasks. We interpret these results in the context of other mental transformation tasks, such as mental rotation in the visual domain, which are known to recruit the intraparietal sulcus region, and we propose that this region subserves general computations that require transformations of a sensory input. Mental imagery tasks may thus have both task or modality-specific components as well as components that supersede any specific codes and instead represent amodal mental manipulation.

Behavioral and neural correlates of perceived and imagined musical timbre

The generality of findings implicating secondary auditory areas in auditory imagery was tested by using a timbre imagery task with fMRI. Another aim was to test whether activity in supplementary motor area (SMA) seen in prior studies might have been related to subvocalization. Participants with moderate musical background were scanned while making similarity judgments about the timbre of heard or imagined musical instrument sounds. The critical control condition was a visual imagery task. The pattern of judgments in perceived and imagined conditions was similar, suggesting that perception and imagery access similar cognitive representations of timbre. As expected, judgments of heard timbres, relative to the visual imagery control, activated primary and secondary auditory areas with some right-sided asymmetry. Timbre imagery also activated secondary auditory areas relative to the visual imagery control, although less strongly, in accord with previous data. Significant overlap was observed in these regions between perceptual and imagery conditions. Because the visual control task resulted in deactivation of auditory areas relative to a silent baseline, we interpret the timbre imagery effect as a reversal of that deactivation. Despite the lack of an obvious subvocalization component to timbre imagery, some activity in SMA was observed, suggesting that SMA may have a more general role in imagery beyond any motor component.

Identification, discrimination, and selective adaptation of simultaneous musical intervals

Four experiments investigated perception of major and minor thirds whose component tones were sounded simultaneously. Effects akin to categorical perception of speech sounds were found. In the first experiment, musicians demonstrated relatively sharp category boundaries in identification and peaks near the boundary in discrimination tasks of an interval continuum where the bottom note was always an F and the top note varied from A to A flat in seven equal logarithmic steps. Nonmusicians showed these effects only to a small extent. The musicians showed higher than predicted discrimination performance overall, and reaction time increases at category boundaries. In the second experiment, musicians failed to consistently identify or discriminate thirds which varied in absolute pitch, but retained the proper interval ratio. In the last two experiments, using selective adaptation, consistent shifts were found in both identification and discrimination, similar to those found in speech experiments. Manipulations of adapting and test showed that the mechanism underlying the effect appears to be centrally mediated and confined to a frequency-specific level. A multistage model of interval perception, where the first stages deal only with specific pitches may account for the results.

Hearing in the mind's ear: A PET investigation of musical imagery and perception

Neuropsychological studies have suggested that imagery processes may be mediated by neuronal mechanisms similar to those used in perception. To test this hypothesis, and to explore the neural basis for song imagery, 12 normal subjects were scanned using the water bolus method to measure cerebral blood flow (CBF) during the performance of three tasks. In the control condition subjects saw pairs of words on each trial and judged which word was longer. In the perceptual condition subjects also viewed pairs of words, this time drawn from a familiar song; simultaneously they heard the corresponding song, and their task was to judge the change in pitch of the two cued words within the song. In the imagery condition, subjects performed precisely the same judgment as in the perceptual condition, but with no auditory input. Thus, to perform the imagery task correctly an internal auditory representation must be accessed. Paired-image subtraction of the resulting pattern of CBF, together with matched MRI for anatomical localization, revealed that both perceptual and imagery. tasks produced similar patterns of CBF changes, as compared to the control condition, in keeping with the hypothesis. More specifically, both perceiving and imagining songs are associated with bilateral neuronal activity in the secondary auditory cortices, suggesting that processes within these regions underlie the phenomenological impression of imagined sounds. Other CBF foci elicited in both tasks include areas in the left and right frontal lobes and in the left parietal lobe, as well as the supplementary motor area. This latter region implicates covert vocalization as one component of musical imagery. Direct comparison of imagery and perceptual tasks revealed CBF increases in the inferior frontal polar cortex and right thalamus. We speculate that this network of regions may be specifically associated with retrieval and/or generation of auditory information from memory.

Can You Hear the Shape of a Drum?

If you had perfect pitch and listened to a recording of the sounds a drum made when struck, could you determine the shape of the drum? This question is an example of an inverse problem; inverse problems arise in medical imaging, oil prospecting, spectroscopy, and many other fields. We’ll first discuss the analogous question in the simpler setting of plucking a string. Then we’ll tackle the problem for drums and see that there are some surprises. Finally, I will give a brief indication of how this problem relates to some of my recent research. The emphasis will be on the ideas rather than on the technical details, so there will be pretty pictures instead of equations.

Evidence for impaired sound intensity processing in schizophrenia

Patients with schizophrenia are impaired in many aspects of auditory processing, but indirect evidence suggests that intensity perception is intact. However, because the extraction of meaning from dynamic intensity relies on structures that appear to be altered in schizophrenia, we hypothesized that the perception of auditory looming is impaired as well. Twenty inpatients with schizophrenia and 20 control participants, matched for age, gender, and education, gave intensity ratings of rising (looming) and falling intensity sounds with different mean intensities. Intensity change was overestimated in looming as compared with receding sounds in both groups. However, healthy individuals showed a stronger effect at higher mean intensity, in keeping with previous findings, while patients with schizophrenia lacked this modulation. We discuss how this might support the notion of a more general deficit in extracting emotional meaning from different sensory cues, including intensity and pitch.