Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 8 de 8
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Rev Sci Instrum ; 86(7): 075004, 2015 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-26233405

RESUMO

A transducer based on a virtual flow meter is proposed for monitoring helium distribution and consumption in cryogenic systems for particle accelerators. The virtual flow meter allows technical and economical constraints, preventing installation of physical instruments in all the needed measurement points, to be overcome. Virtual flow meter performance for the alternative models of Samson [ http://www.samson.de (2015)] and Sereg-Schlumberger [ http://www.slb.com/ (2015)] is compared with the standard IEC 60534-2-1 [Industrial-process control valves-Part 2-1: Flow capacity-sizing equations for fluid flow under installed conditions (2011), https://webstore.iec.ch/publication/2461], for a large temperature range, for both gaseous and liquid helium phases, and for different pressure drops. Then, the calibration function of the transducer is derived. Finally, the experimental validation for the helium gaseous state on the test station for superconducting magnets in the laboratory SM18 [Pirotte et al., AIP Conf. Proc. 1573, 187 (2014)] at CERN is reported.

2.
Rev Sci Instrum ; 86(12): 125001, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26724060

RESUMO

The metrological performance of a virtual flowmeter-based transducer for monitoring helium under cryogenic conditions is assessed. At this aim, an uncertainty model of the transducer, mainly based on a valve model, exploiting finite-element approach, and a virtual flowmeter model, based on the Sereg-Schlumberger method, are presented. The models are validated experimentally on a case study for helium monitoring in cryogenic systems at the European Organization for Nuclear Research (CERN). The impact of uncertainty sources on the transducer metrological performance is assessed by a sensitivity analysis, based on statistical experiment design and analysis of variance. In this way, the uncertainty sources most influencing metrological performance of the transducer are singled out over the input range as a whole, at varying operating and setting conditions. This analysis turns out to be important for CERN cryogenics operation because the metrological design of the transducer is validated, and its components and working conditions with critical specifications for future improvements are identified.

3.
Rev Sci Instrum ; 85(9): 095103, 2014 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-25273768

RESUMO

Evolutionary approach to centralized multiple-faults diagnostics is extended to distributed transducer networks monitoring large experimental systems. Given a set of anomalies detected by the transducers, each instance of the multiple-fault problem is formulated as several parallel communicating sub-tasks running on different transducers, and thus solved one-by-one on spatially separated parallel processes. A micro-genetic algorithm merges evaluation time efficiency, arising from a small-size population distributed on parallel-synchronized processors, with the effectiveness of centralized evolutionary techniques due to optimal mix of exploitation and exploration. In this way, holistic view and effectiveness advantages of evolutionary global diagnostics are combined with reliability and efficiency benefits of distributed parallel architectures. The proposed approach was validated both (i) by simulation at CERN, on a case study of a cold box for enhancing the cryogeny diagnostics of the Large Hadron Collider, and (ii) by experiments, under the framework of the industrial research project MONDIEVOB (Building Remote Monitoring and Evolutionary Diagnostics), co-funded by EU and the company Del Bo srl, Napoli, Italy.

4.
Stud Health Technol Inform ; 70: 89-95, 2000.
Artigo em Inglês | MEDLINE | ID: mdl-10977590

RESUMO

A novel ankle rehabilitation device is being developed for home use, allowing remote monitoring by therapists. The system will allow patients to perform a variety of exercises while interacting with a virtual environment (VE). These game-like VEs created with WorldToolKit run on a host PC that controls the movement and output forces of the device via an RS232 connection. Patients will develop strength, flexibility, coordination, and balance as they interact with the VEs. The device will also perform diagnostic functions, measuring the ankle's range of motion, force exertion capabilities and coordination. The host PC transparently records patient progress for remote evaluation by therapists via our existing telerehabilitation system. The "Rutgers Ankle" Orthopedic Rehabilitation Interface uses double-acting pneumatic cylinders, linear potentiometers, and a 6 degree-of-freedom (DOF) force sensor. The controller contains a Pentium single-board computer and pneumatic control valves. Based on the Stewart platform, the device can move and supply forces and torques in 6 DOFs. A proof-of-concept trial conducted at the University of Medicine and Dentistry of New Jersey (UMDNJ) provided therapist and patient feedback. The system measured the range of motion and maximum force output of a group of four patients (male and female). Future medical trials are required to establish clinical efficacy in rehabilitation.


Assuntos
Traumatismos do Tornozelo/reabilitação , Processamento de Imagem Assistida por Computador , Procedimentos Ortopédicos , Consulta Remota , Interface Usuário-Computador , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Sistemas Computadorizados de Registros Médicos , Microcomputadores , Pessoa de Meia-Idade , Modalidades de Fisioterapia/instrumentação , Amplitude de Movimento Articular
5.
Stud Health Technol Inform ; 62: 261-7, 1999.
Artigo em Inglês | MEDLINE | ID: mdl-10538369

RESUMO

A PC-based orthopedic rehabilitation system was developed for use at home, while allowing for remote monitoring from the clinic. The home rehabilitation station has a Pentium II PC with graphics accelerator, Polhemus tracker, and a novel Multipurpose Haptic Control Interface with its own Pentium board. This interface is used to sample patient's hand positions and to provide resistive forces using the Rutgers Master II (RMII) glove. A library of virtual rehabilitation routines was developed using WorldToolKit software. At the present time, it consists of two physical therapy exercises (DigiKey and Ball) and two functional rehabilitation exercises (Peg Board test and Ball game). All VR exercises allow automatic and transparent patient data collection into an Oracle database. A remote Pentium II PC is connected with the home-based PC over the Internet and an additional video-conferencing connection. The remote computer running Oracle server is used to maintain the patient database, monitor progress and change exercise level of difficulty. This allows for timely patient progress monitoring and repeat evaluations over time from the Clinic. The system will soon start clinical trails at Stanford Medical School, with progress being monitored remotely from Rutgers University. Other rehabilitation haptic interfaces under development include devices for elbow, and knee rehabilitation connected to the Multipurpose Haptic Control Interface.


Assuntos
Terapia por Exercício/métodos , Traumatismos da Mão/reabilitação , Microcomputadores , Telemedicina/instrumentação , Terapia Assistida por Computador , Interface Usuário-Computador , Gráficos por Computador , Humanos , Software
6.
Phys Rev Lett ; 76(17): 3061-3064, 1996 Apr 22.
Artigo em Inglês | MEDLINE | ID: mdl-10060866
7.
Eur J Pharmacol ; 101(3-4): 193-200, 1984 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-6547908

RESUMO

The effects of pirenzepine and atropine on gastric emptying, gastric secretion and heart rate were studied in rats. Both drugs inhibited gastric emptying and secretion dose dependently and increased pulse rate. In the gastric secretory studies both compounds displayed potencies which were not very dissimilar (ID50 were 8.1 mumol X kg-1 and 1.4 mumol X kg-1 for pirenzepine and atropine respectively, potency ratio 6); pirenzepine was however decidedly less potent than atropine in inhibiting gastric emptying (potency ratio 36 on a molar basis) and in increasing heart rate (potency ratio 125). These data, in accordance with results of clinical trials, indicate that pirenzepine-unlike atropine-can inhibit acid secretion without appreciably affecting gastric motility and cardiac function.


Assuntos
Atropina/farmacologia , Benzodiazepinonas/farmacologia , Esvaziamento Gástrico/efeitos dos fármacos , Mucosa Gástrica/efeitos dos fármacos , Parassimpatolíticos/farmacologia , Animais , Mucosa Gástrica/metabolismo , Frequência Cardíaca/efeitos dos fármacos , Cinética , Masculino , Pirenzepina , Ratos , Ratos Endogâmicos
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...