27 research outputs found
A Non Invasive Heart Rate and Blood Pressure Remote Monitoring System
Health monitoring systems have become an important research field today. Research on health monitoring were developed for many applications such as in home care units, emergency monitoring systems etc. This paper proposes the design of a non invasive wireless heart rate and blood pressure remote monitoring system based on an embedded board and Bluetooth wireless technology. The real time biomedical signal is sensed and measured using an optical measurement circuit based on Photoplethysmography technique. Blood pressure and heart rate readings are calculated on the basis of the developed algorithm and are displayed on the LCD screen. Moreover these numerical values of heart rate, systolic and diastolic pressure can be transmitted to any bluetooth enabled computer or smart phone via Bluetooth wireless technology
Thermostat for non-equilibrium multiparticle collision dynamics simulations
Multiparticle collision dynamics (MPC), a particle-based mesoscale simulation
technique for com- plex fluid, is widely employed in non-equilibrium
simulations of soft matter systems. To maintain a defined thermodynamic state,
thermalization of the fluid is often required for certain MPC variants. We
investigate the influence of three thermostats on the non-equilibrium
properties of a MPC fluid under shear or in Poiseuille flow. In all cases, the
local velocities are scaled by a factor, which is either determined via a local
simple scaling approach (LSS), a Monte Carlo-like procedure (MCS), or by the
Maxwell-Boltzmann distribution of kinetic energy (MBS). We find that the
various scal- ing schemes leave the flow profile unchanged and maintain the
local temperature well. The fluid viscosities extracted from the various
simulations are in close agreement. Moreover, the numerically determined
viscosities are in remarkably good agreement with the respective theoretically
predicted values. At equilibrium, the calculation of the dynamic structure
factor reveals that the MBS method closely resembles an isothermal ensemble,
whereas the MCS procedure exhibits signatures of an adi- abatic system at
larger collision-time steps. Since the velocity distribution of the LSS
approach is non-Gaussian, we recommend to apply the MBS thermostat, which has
been shown to produce the correct velocity distribution even under
non-equilibrium conditions.Comment: 12 pages, 5 figures in Phys. Rev. E, 201
Hydrodynamic correlations in shear flow: A Multiparticle--Collision--Dynamics simulation study
The nonequilibrium hydrodynamic correlations of a
Multiparticle-Collision-Dynamics (MPC) fluid in shear flow are studied by
analytical calculations and simulations. The Navier-Stokes equations for a MPC
fluid are linearized about the shear flow and the hydrodynamic modes are
evaluated as an expansion in the momentum vector. The shear-rate dependence and
anisotropy of the transverse and longitudinal velocity correlations are
analyzed. We demonstrate that hydrodynamic correlations in shear flow are
anisotropic, specifically, the two transverse modes are no longer identical. In
addition, our simulations reveal the directional dependence of the frequency
and attenuation of the longitudinal velocity correlation function. Furthermore,
the velocity autocorrelation functions of a tagged fluid particle in shear flow
are determined. The simulations results for various hydrodynamic correlations
agree very well with the theoretical predictions.Comment: 8 pages, 5 figure
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Cortical Reorganisation in Complex Regional Pain Syndrome (CRPS)
Complex Regional Pain Syndrome (CRPS) is a debilitating pain condition of unknown aetiology, usually occurring post-traumatically. Early diagnosis of CRPS remains a challenge with adverse implications on rehabilitation and recovery. The main goals of my research were to help develop clinically useful bedside tests as well as objective biomarkers to improve the early diagnosis of CRPS.
The first research project in this thesis, ‘Novel signs in CRPS and their diagnostic clinical utility’ was a prospective observational cohort study which defined the four novel signs (finger misperception, abnormal hand laterality, astereognosis and abnormal body scheme report) in CRPS, examined their prevalence in CRPS and other chronic pain conditions and assessed their diagnostic utility (Sensitivity, Specificity, Predictive values and Likelihood ratios) for identifying patients at risk of CRPS within a Fracture cohort. This study demonstrates that novel signs are present in the majority of CRPS patients and can be reliably detected following simple training. They are practical and have significant clinical utility in diagnosing persistent pain in a fracture group. They can be used to identify patients at high risk of developing chronic pain post-fracture thereby allowing targeted early intervention.
Cortical reorganisation, defined as structural and functional changes within the cerebral cortex, is implicated in many chronic pain conditions including CRPS. The second research project in this thesis ‘Cortical reorganisation and finger misperception in CRPS- a high density electroencephalogram study’ was a prospective case control design study which investigated the EEG parameters suggestive of cortical reorganisation in CRPS patients by studying the somatosensory ERPs (Event Related Potentials) elicited on painless finger stimulation. There was no significant difference in the GFP (Global Field Power) latency in the patient group compared to healthy subjects or between affected and unaffected sides of the patient group suggesting there was no impairment of somatosensory conduction from the periphery to the somatosensory cortex. However, GFP amplitude corresponding to P300 was significantly higher in the patient affected side compared to the healthy subjects suggesting cognitive dysfunction possibly related to increased allocation of attentional resources
Ensemble Equivalence for Counterion Condensation on a Two Dimensional Charged Disc
We study the counterion condensation on a two dimensional charged disc in the
limit of infinite dilution, and compare the energy-temperature relation
obtained from the canonical free energy and microcanonical entropy. The
microcanonical entropy is piecewise linear in energy, and is shown to be
concave for all energies. As a result, even though the interactions are
long-ranged, the energy-temperature relation and hence the counterion
condensation transition points are identical in both the ensembles.Comment: 4 pages, 2 figure
Phase transitions of a single polyelectrolyte in a poor solvent with explicit counterions
Conformational properties of a single flexible polyelectrolyte chain in a
poor solvent are studied using constant temperature molecular dynamics
simulation. The effects of counterions are explicitly taken in to account.
Structural properties of various phases and the transition between these phases
are studied by tracking the values of asphericity, radius of gyration, fraction
of condensed counterions, number of non-bonded neighbours and Coulomb
interaction energies. From our simulations, we find strong evidence for a
first-order phase transition from extended to collapsed phase consistent with
earlier theoretical predictions. We also identify a continuous phase transition
associated with the condensation of counterions and estimate the critical
exponents associated with the transition. Finally, we argue that previous
suggestions of existence of an independent intermediate phase between extended
and collapsed phases is only a finite size effect.Comment: 7 pages, 8 figure
Time correlation functions in the Lebwohl-Lasher model of liquid crystals
Time correlation functions in the Lebwohl-Lasher model of nematic liquid crystals are studied using theory and
molecular dynamics simulations. In particular, the autocorrelation functions of angular momentum and nematic director fluctuations are calculated in the long-wavelength limit. The constitutive relations for the hydrodynamic currents are derived using a standard procedure based on non-negativity of the entropy production. The continuity equations are then linearized and solved to calculate the correlation functions. We find that the transverse angular momentum fluctuations are coupled to the director fluctuations, and are both propagative. The propagative nature of the fluctuations suppress the anticipated hydrodynamic long-time tails in the single-particle autocorrelation functions. The fluctuations in the isotropic phase are however diffusive, leading to long-time tails in spatial dimensions. The Frank elastic constant measured using the time-correlation functions are in good agreement with previously reported results
B-mode and Doppler ultrasound features of mammary neoplasms and their comparison with normal mammary glands in dogs
Canine mammary neoplasms are naturally occurring non-homogenous group of
tumours with many resemblances to human breast cancer. In female dogs mammary tumours
are of great clinical relevance due to the high prevalence and mortality rate, which varies
according to the histopathological classification and clinical stage. The aim of the study was to
compare the ultrasonographic features of the normal mammary gland with benign and malignant
mammary neoplasms in dogs, through assessed by B-mode and Doppler mode ultrasonography.
Ultrasonographic examination of seven normal mammary glands along with six benign and 12
malignant mammary neoplasms were performed. Among the parameters evaluated by B-Mode
ultrasonography, significant differences were found (p < 0.01) in the tumour margin and invasiveness
of neoplasms, where malignant tumours were invasive with uncircumscribed margin. Significant
difference was also found in the presence of posterior acoustic enhancement (p<0.05) between
benign and malignant mammary neoplasms. Elevated peak systolic velocity of blood flow within
the tumour vessels in malignant mammary neoplasm was the only feature assessed with Doppler
mode having significant difference