Cardiac Response to Live Music Performance: Computing Techniques for Feature Extraction and Analysis

Strong emotions and mental stress have been linked to potentially deadly arrhythmias. Music evokes strong emotion through the regulation of tension and release and the modulation of changes and transitions. We exploit this in a novel study involving patients with implanted cardiac defibrillators to study the impact of live music performance on cardiac electrophysiology. The patients’ heart rates are artificially fixed with pacing at the higher of 80 beats per minute or 10 above the heart’s intrinsic rate. We make continuous recordings directly from the heart muscle whilst the patients are listening to a short classical music concert, which is concurrently recorded in a separate stream. The participants provide annotations of perceived boundaries/transitions and felt tension. The recorded cardiac and music information is further processed to extract relevant features. Here, we describe the experiment design, and the mathematical and computing techniques used to represent and abstract the features from the recorded data. Cardiac reaction is measured by the action potential duration (APD), approximated using the action recovery interval (ARI). The expressive parameters extracted from the music include the time varying loudness, tempo, and harmonic tension. The synchronized information layers allow for detailed analysis of immediate cardiac response to dynamically varying expressive nuances in performed music

Putting (One's) Heart into Music

International audienc

Gigantic transmission band edge resonance in periodic stacks of anisotropic layers

We consider Fabry-Perot cavity resonance in periodic stacks of anisotropic layers with misaligned in-plane anisotropy at the frequency close to a photonic band edge. We show that in-plane dielectric anisotropy can result in a dramatic increase in field intensity and group delay associated with the transmission resonance. The field enhancement appears to be proportional to forth degree of the number N of layers in the stack. By contrast, in common periodic stacks of isotropic layers, those effects are much weaker and proportional to N^2. Thus, the anisotropy allows to drastically reduce the size of the resonance cavity with similar performance. The key characteristic of the periodic arrays with the gigantic transmission resonance is that the dispersion curve omega(k)at the photonic band edge has the degenerate form Delta(omega) ~ Delta(k)^4, rather than the regular form Delta(omega) ~ Delta(k)^2. This can be realized in specially arranged stacks of misaligned anisotropic layers. The degenerate band edge cavity resonance with similar outstanding properties can also be realized in a waveguide environment, as well as in a linear array of coupled multimode resonators, provided that certain symmetry conditions are in place.Comment: To be submitted to Phys. Re

A Self-Organized Method for Computing the Epidemic Threshold in Computer Networks

In many cases, tainted information in a computer network can spread in a way similar to an epidemics in the human world. On the other had, information processing paths are often redundant, so a single infection occurrence can be easily "reabsorbed". Randomly checking the information with a central server is equivalent to lowering the infection probability but with a certain cost (for instance processing time), so it is important to quickly evaluate the epidemic threshold for each node. We present a method for getting such information without resorting to repeated simulations. As for human epidemics, the local information about the infection level (risk perception) can be an important factor, and we show that our method can be applied to this case, too. Finally, when the process to be monitored is more complex and includes "disruptive interference", one has to use actual simulations, which however can be carried out "in parallel" for many possible infection probabilities

Dr. Martin Hillenbrand to Receive University of Dayton Distinguished Alumnus Award

News release announcing the University of Dayton will Award Assistant Secretary of State for European Affairs, Dr. Martin Hillenbrand, with the Distinguished Alumnus Award

Atrial Fibrillation Stratification via Fibrillatory Wave Characterization Using the Filter Diagonalization Method

We use the Filter Diagonalization Method (FDM), a harmonic inversion technique, to extract f-wave features in electrocardiographic (ECG) traces for atrial fibrillation (AF) stratification. The FDM detects f-wave frequencies and amplitudes at frame sizes of 0.15 seconds. We demonstrate our method on a dataset comprising of ECG recordings from 23 patients (61.65 ± 11.63 years, 78.26% male) before cryoablation; 2 paroxysmal AF, 16 early persistent AF (12 months duration). Moreover, some of these patients received adenosine to enhance their RR intervals before ablation. Our method extracts features from FDM outputs to train statistical machine learning classifiers. Tenfold cross-validation demonstrates that the Random Forest and Decision Tree models performed best for the pre-ablation without and with adenosine datasets, with accuracy 60.89 ± 0.31% and 59.58% ± 0.04%, respectively. While the results are modest, they demonstrate that f-wave features can be used for AF stratification. The accuracies are similar for the two tests, slightly better for the case without adenosine, showing that the FDM can successfully model short f-waves without the need to concatenate f-wave sequences or adenosine to elongate RR intervals

Balancing Minimum Spanning and Shortest Path Trees

This paper give a simple linear-time algorithm that, given a weighted digraph, finds a spanning tree that simultaneously approximates a shortest-path tree and a minimum spanning tree. The algorithm provides a continuous trade-off: given the two trees and epsilon > 0, the algorithm returns a spanning tree in which the distance between any vertex and the root of the shortest-path tree is at most 1+epsilon times the shortest-path distance, and yet the total weight of the tree is at most 1+2/epsilon times the weight of a minimum spanning tree. This is the best tradeoff possible. The paper also describes a fast parallel implementation.Comment: conference version: ACM-SIAM Symposium on Discrete Algorithms (1993

A motivational intervention for patients with COPD in primary care: Qualitative evaluation of a new practitioner role.

Methods: Qualitative study using patient and practice staff informants. We audio-recorded interviews with 29 patients offered the intervention (three had declined it or withdrawn) and 13 practice staff (GPs, nurses and administrators). Analysis used a constant comparative approach. Background: Long-term conditions such as chronic obstructive pulmonary disease (COPD) are growing challenges for health services. Psychosocial co-morbidity is associated with poorer quality of life and greater use of health care in these patients but is often un-diagnosed or inadequately treated in primary care, where most care for these patients is provided. We developed a brief intervention, delivered by 'liaison health workers' (LHWs), to address psychosocial needs in the context of an integrated approach to physical and mental health. We report a qualitative study in which we characterize the intervention through the experience of the patients receiving it and examine how it was incorporated into primary care. Results: Most patients were enthusiastic about the LHWs, describing the intervention as mobilizing their motivation for self-management. By contrast with other practitioners, patients experienced the LHWs as addressing their needs holistically, being guided by patient needs rather than professional agendas, forming individual relationships with patients and investing in patients and their capacity to change. Practices accommodated and accepted the LHWs, but positioned them as peripheral to and separate from the priority of physical care. Conclusions: Despite being a short-term intervention, patients described it as having enduring motivational benefits. The elements of the intervention that patients described map onto the key features of motivating interventions described by Self-Determination Theory. We suggest that the LHWs motivated patients to self-management by: (i) respecting patients' competence to decide on needs and priorities; (ii) forming relationships with patients as individuals; and (iii) fostering patients' sense of autonomy. While truly integrated primary care for patients with long-term conditions such as COPD remains elusive, existing practice staff might adopt elements of the LHWs' approach to enhance motivational change in patients with long-term conditions such as COPD

Dispersive forces on bodies and atoms: a unified approach

A unified approach to the calculation of dispersive forces on ground-state bodies and atoms is given. It is based on the ground-state Lorentz force density acting on the charge and current densities attributed to the polarization and magnetization in linearly, locally, and causally responding media. The theory is applied to dielectric macro- and micro-objects, including single atoms. Existing formulas valid for weakly polarizable matter are generalized to allow also for strongly polarizable matter. In particular when micro-objects can be regarded as single atoms, well-known formulas for the Casimir-Polder force on atoms and the van der Waals interaction between atoms are recovered. It is shown that the force acting on medium atoms--in contrast to isolated atoms--is in general screened by the other medium atoms.Comment: 10 pages, 2 embedded figure

Extra-corporeal membrane oxygenation in the management of 2009 influenza A (H1N1) refractory respiratory failure.

Rapidly progressive acute respiratory failure attributed to 2009 H1N1 influenza A infection has been reported worldwide-3. Refractory hypoxaemia despite conventional mechanical ventilation and lung protective strategies has resulted in the use a combination of rescue therapies, such as conservative fluid management, prone positioning, inhaled nitric oxide, high frequency oscillatory ventilation and extracorporeal membrane oxygenation (ECMO)4. ECMO allows for pulmonary or cardiopulmonary support as an adjunct to respiratory and cardiac failure, minimising ventilator-associated lung injury (VALI). This permits treatment of the underlying disease process, while concurrently allowing for recovery of the acute lung injury. This case documents a previously healthy twenty-two year old Asian male patient with confirmed pandemic (H 1N1) 2009 influenza A who was successfully managed with ECMO in the setting of severe refractory hypoxaemia and progressive hypercapnia