Search results for "Gram"

Optical multichannel monitoring of skin blood pulsations for cardiovascular assessment

2004

Time resolved detection and analysis of the skin back-scattered optical signals (reflection photoplethysmography or PPG) provide rich information on skin blood volume pulsations and can serve for cardiovascular assessment. The multichannel PPG concept has been developed and clinically verified in this work. Simultaneous data flow from several body locations allows to study the heartbeat pulse wave propagation in real time and to evaluate the vascular resistance. Portable two- and four-channel PPG monitoring devices and special software have been designed for real-time data acquisition and processing. The multi-channel devices were successfully applied for cardiovascular fitness tests and fo…

ESRA19-0692 Which preoperative tests before regional anaesthetic procedures?

2019

As we know, any regional anaesthesia technique stays under failure risks. What anaesthetists have to know about the regional block before let the surgeons start after regional anaesthesia? There are few positions which should be confirmed by tests. Firstly, detect the onset of successful sensitive, motor and sympathetic block. Secondly, confirm the correct area of the regional block. Furthermore, the anaesthetist should understand if the regional block performed under deep sedation or general anaesthesia will be effective also after the surgery. What we have to remember and what we need to check for this reason? Pain is subjective phenomenon. Are we determined as dependent on the patient‘s …

Pericytes: a target for in vivo reprogramming?

2013

Identical fits of nonnegative matrix/tensor factorization may correspond to different extracted event-related potentials

2010

Nonnegative Matrix / Tensor factorization (NMF/NTF) have been used in the study of EEG, and the fit (explained variation) is often used to evaluate the performance of a nonnegative decomposition algorithm. However, this parameter only reveals the information derived from the mathematical model and just exhibits the reliability of the algorithms, and the property of EEG can not be reflected. If fits of two algorithms are identical, it is necessary to examine whether the desired components extracted by them are identical too. In order to verify this doubt, we performed NMF and NTF on the same dataset of an auditory event-related potentials (ERPs), and found that the identical fits of NMF and …

GPCALMA: An Italian mammographic database of digitized images for research

2006

In this work the implementation of a database of digitized mammograms is described. The digitized images were collected since 1999 by a community of physicists in collaboration with radiologists in several Italian hospitals, as a first step in order to develop and implement a Computer Aided Detection (CAD) system. 3369 mammograms were collected from 967 patients; they were classified according to the type and the morphology of the lesions, the type of the breast tissue and the type of pathologies. A dedicated Graphical User Interface was developed for mammography visualization and processing, in order to support the medical diagnosis directly on a high-resolution screen. The database has be…

Optical Studies of the Capillary Refill Kinetics in Fingertips

2009

A new methodology for temporal analysis of the capillary refill processes by means of photoplethysmography (PPG) contact probe operating in the blue region of spectrum has been developed. A corresponding prototype device for finger measurements has been created and clinically tested. Results demonstrated that both AC and DC components of the blue PPG bio-signals are sensitive to the capillary occlusion and refill. Real-time measurements of the skin capillary refill kinetics by this technology can be used for noninvasive diagnostics of the peripheral perfusion disorders.

Tips and tricks for flow cytometry-based analysis and counting of microparticles

2015

Submicron-sized extra-cellular vesicles generated by budding from the external cell membranes, microparticles (MPs) are important actors in transfusion as well as in other medical specialties. After briefly positioning their role in the characterization of labile blood products, this technically oriented chapter aims to review practical points that need to be considered when trying to use flow cytometry for the analysis, characterization and absolute counting of MP subsets. Subjects of active discussions relative to instrumentation will include the choice of the trigger parameter, possible standardization approaches requiring instrument quality-control, origin and control of non-specific ba…

The number of contacts in random fibre networks

2012

There is a wide range of materials that can be considered as nonwoven random networks of fibres. Such materials include glass-fibre mats, filters, various paper products and structural components of cells and tissues. The mechanical properties of these kinds of networks have been studied extensively for many decades. As many of such networks form more or less two-dimensional structures, they can, to a good approximation, be considered to consist of randomly distributed fibres or filaments connected at their crossings points. Recent development of the resolution of X-ray computed tomography have enabled imaging of the three dimensional structure of such materials with a resolution sufficient…

Classification of Schizophrenia Patients and Healthy Controls Using ICA of Complex-Valued fMRI Data and Convolutional Neural Networks

2019

Deep learning has contributed greatly to functional magnetic resonance imaging (fMRI) analysis, however, spatial maps derived from fMRI data by independent component analysis (ICA), as promising biomarkers, have rarely been directly used to perform individualized diagnosis. As such, this study proposes a novel framework combining ICA and convolutional neural network (CNN) for classifying schizophrenia patients (SZs) and healthy controls (HCs). ICA is first used to obtain components of interest which have been previously implicated in schizophrenia. Functionally informative slices of these components are then selected and labelled. CNN is finally employed to learn hierarchical diagnostic fea…

Miniature wireless photoplethysmography devices: integration in garments and test measurements

2012

Wireless PPG devices were developed and embedded in everyday clothes (bandage, scarf, cycling glove and wrist strap) to monitor cardiovascular state of free-moving persons. The corresponding software for measurements also has been developed and tested in laboratory. Real-time measurements of PPG signals were taken in parallel with a professional ECG reference device, and high correlation was demonstrated.