Estimation of heart rate and respiratory rate by monitoring cardiopulmonary signals with flexible sensor.

Monitoring of cardiopulmonary signals plays an important role in many clinical applications. A portable magnetic induction cardiopulmonary signal monitoring system with the flexible sensor of double micro-coils is presented in this paper. The detection of cardiopulmonary signals is realized with double micro-coils. The proposed system is safe, non-invasive, simple, and portable compared with traditional direct contact methods. The Hilbert-Huang transform (HHT) based on complete ensemble empirical mode decomposition with adaptive noise (CEEMDAN) is applied to cardiopulmonary signal processing, decomposing cardiopulmonary signal effectively. The sensor to monitor respiration rate and heart rate is validated and demonstrated with healthy volunteers. The root mean squared errors (RMSE) of heart rate, respiration rate under deep breathing and normal breathing are 3.8 beats/min, 0.61 times/min, and 0.98 times/min respectively. The flexible sensor of double micro-coils has little influence on the measurement results at the bending curvature of 33.9 m-1. Therefore, a suggested solution for monitoring and decomposition of cardiopulmonary signals is easy-to-use, and quick, which can be applied as a respected analytical device on mobile occasions in this study.

Erratum: Signatures for Wigner Crystal Formation in the Chemical Potential of a Two-Dimensional Electron System [Phys. Rev. Lett. 113, 076804 (2014)].

This corrects the article DOI: 10.1103/PhysRevLett.113.076804.

Signatures for Wigner crystal formation in the chemical potential of a two-dimensional electron system.

We investigate the evolution of the chemical potential of a two-dimensional electron system (2DES) as a function of density at a fixed magnetic field. By using a bilayer system, changes in the chemical potential of one 2DES are determined from the density variation induced in the second, nearby 2DES. At high magnetic fields around a filling factor of ν=1 or ν=2, the chemical potential jump associated with the condensation in a quantum Hall state exhibits two anomalies symmetrically located around these integer filling factors. They are attributed to the formation of a 2D Wigner crystal of quasiparticles.

Electronic transport in two stacked graphene monolayers.

We report on interlayer and lateral electronic transport measurements in two stacked graphene monolayers which have separate electrical contacts. The current-voltage characteristic across the two layers shows linear Ohmic behavior at zero magnetic field. At high magnetic fields, sequences of quantum Hall plateaus of the overlap region with filling factors 4, 8, and 12 are observed which can be explained by equilibration of the edge channel potentials of the individual graphene layers. An anomaly is observed at total filling factors ±2 in the overlap region. The I-V characteristic for interlayer transport turns nonlinear, and the Hall signal vanishes, indicating a magnetic field induced electrical decoupling of the two graphene layers.