The Experts below are selected from a list of 98655 Experts worldwide ranked by ideXlab platform
David Ewins - One of the best experts on this subject based on the ideXlab platform.
-
Gait event detection on level ground and incline walking using a rate gyroscope
Sensors, 2010Co-Authors: Paola Catalfamo, Salim Ghoussayni, David EwinsAbstract:Gyroscopes have been proposed as sensors for ambulatory gait analysis and functional electrical stimulation systems. Accurate determination of the Initial Contact of the foot with the floor (IC) and the final contact or Foot Off (FO) on different terrains is important. This paper describes the evaluation of a gyroscope placed on the shank for determination of IC and FO in subjects walking outdoors on level ground, and up and down an incline. Performance was compared with a Reference Pressure measurement system. The mean difference between the gyroscope and the Reference was less than –25 ms for IC and less than 75 ms for FO for all terrains. Detection success was over 98%. These results provide preliminary evidence supporting the use of the gyroscope for gait event detection on inclines as well as level walking.
Petros Taoukis - One of the best experts on this subject based on the ideXlab platform.
-
kinetic study of high Pressure microbial and enzyme inactivation and selection of pasteurisation conditions for valencia orange juice
International Journal of Food Science and Technology, 2010Co-Authors: George Katsaros, Maria Tsevdou, Theodora Panagiotou, Petros TaoukisAbstract:Summary Keeping quality of fresh orange juice is highly dependent on pectinolytic enzyme activity and the growth of spoilage microorganisms. The inactivation kinetics of indigenous pectin methylesterase (PME) and of the two more Pressure resistant species of spoilage lactic acid bacteria (LAB) Lactobacillus plantarum and L. brevis in freshly squeezed Valencia orange juice under high hydrostatic Pressure (100–500 MPa) combined with moderate temperature (20–40 °C) was investigated. PME inactivation followed first order kinetics with a residual PME activity (15%) at all Pressure–temperature combinations used. The values of activation energy and activation volume were estimated at each Pressure and at each temperature, respectively. Values of 90 kJ/mol and −30 mL/mol at Reference Pressure of 300 MPa and Reference temperature of 35 °C were estimated respectively. The corresponding zT and zP values of LAB inactivation were also estimated at all conditions tested. Values of 19.5 °C and 95 MPa at Reference Pressure of 300 MPa and Reference temperature of 30 °C were estimated respectively for L. plantarum, while the corresponding values for L. brevis were 40 °C and 82 MPa, respectively, at the same Reference conditions. Pressure and temperature were found to act synergistically both for PME and LAB inactivation. The PME and LAB inactivation rate constants were expressed as functions of the temperature and Pressure process conditions. These functions allow the determination of the Pressure/temperature conditions that achieve the target enzyme and microbial inactivation at a selected processing time. The process conditions of 350 MPa at 35 °C for 2 min are proposed as effective for Valencia orange juice cold pasteurisation.
-
inactivation kinetics of pectin methylesterase of greek navel orange juice as a function of high hydrostatic Pressure and temperature process conditions
Journal of Food Engineering, 2004Co-Authors: A C Polydera, E Galanou, Nikolaos G Stoforos, Petros TaoukisAbstract:Abstract The inactivation kinetics of endogenous pectin methylesterase (PME) in freshly squeezed orange juice under high hydrostatic Pressure (100–800 MPa) combined with moderate temperature (30–60 °C) was investigated. Atmospheric Pressure conditions in a temperature range of 50–80 °C were also tested. PME inactivation followed first order kinetics with a residual PME activity (5–20%) at all Pressure–temperature combinations used. The values of activation energy and activation volume were estimated as 109 kJ mol −1 and −19.76 ml mol −1 at a Reference Pressure of 600 MPa and Reference temperature of 50 °C respectively. Pressure and temperature were found to act synergistically, except in the high temperature–low Pressure region where an antagonistic effect was found. The PME inactivation rate constant was expressed as a function of the temperature and Pressure process conditions used. This function incorporates the observed exponential dependence of activation energy on the Pressure conditions, as well as the linear dependence of activation volume on process temperature.
Howard A. Schwid - One of the best experts on this subject based on the ideXlab platform.
-
Systolic blood Pressure at end-expiration measured by the automated systolic Pressure variation monitor is equivalent to systolic blood Pressure during apnea.
Journal of Clinical Monitoring and Computing, 2000Co-Authors: Howard A. SchwidAbstract:Objective.It is necessary to define a Reference systolic arterial blood Pressure (RP) to calculate delta-Up (dUp) and delta-Down (dDown) for systolic Pressure variation. Most studies define the Reference Pressure as the average systolic blood Pressure during a short period of apnea. We describe an automated systolic Pressure variation monitor that measures airway Pressure and defines the Reference Pressure as the systolic blood Pressure at end-expiration. The present study compares the Reference systolic blood Pressure measured at end-expiration by the automated systolic Pressure variation monitor and the Reference systolic blood Pressure measured during apnea to test whether the end-expiration value is an adequate substitute for the value during apnea. Methods.After obtaining informed consent, 108sets of measurements of systolic Pressure variation (SPV) were made in 20intubated, mechanically-ventilated, anesthetized patients by the automated SPV monitor and during apnea. Measurements were taken during periods of hemodynamic stability defined as three consecutive end-expiratory systolic blood Pressures within four mmHg of each other. The three systolic Pressure sat end-expiration were averaged (RP monitor ). Immediately following these measurements, the ventilator was turned off and the systolic blood Pressure was measured at 6, 8, 10 and 12 seconds of apnea. The Reference Pressure during apnea (RP apnea ) was defined as the average of the systolic blood Pressure at 8, 10 and 12 seconds of apnea. For each measurement set, RP monitor and the systolic blood Pressure at6 seconds of apnea (SBP6) were compared to RP apnea using Bland–Altman analysis. Results.Bland–Altman analysis for the difference between SBP6 and RP apnea yielded a small bias of −0.3 mmHg with standard deviation of 1.3, indicating that the systolic Pressure tends to continue to increase slightly after 6seconds of apnea. Results were similar for the difference between RP monitor and RP apnea (−0.2 ± 3.1mmHg). Conclusions.dUp and dDown are calculated using the Reference Pressure. RP monitor is an average of 0.2 mm Hg less than RP apnea , thus dUp calculated by the automated SPV monitor is an average of 0.2 mm Hg greater than dUp measured by the Reference Pressure during apnea and dDown is 0.2 mm Hg less. Since the bias of −0.2 mm Hgis clinically insignificant, there is acceptable agreement between the Reference Pressure obtained during apnea and that obtained by the automated SPV monitor at end-expiration. The mean difference between RP monitor and RP apnea is explained by the continued rise in systolic Pressure during the period of apnea as demonstrated by the difference between SBP6 and RP apnea .
Paola Catalfamo - One of the best experts on this subject based on the ideXlab platform.
-
Gait event detection on level ground and incline walking using a rate gyroscope
Sensors, 2010Co-Authors: Paola Catalfamo, Salim Ghoussayni, David EwinsAbstract:Gyroscopes have been proposed as sensors for ambulatory gait analysis and functional electrical stimulation systems. Accurate determination of the Initial Contact of the foot with the floor (IC) and the final contact or Foot Off (FO) on different terrains is important. This paper describes the evaluation of a gyroscope placed on the shank for determination of IC and FO in subjects walking outdoors on level ground, and up and down an incline. Performance was compared with a Reference Pressure measurement system. The mean difference between the gyroscope and the Reference was less than –25 ms for IC and less than 75 ms for FO for all terrains. Detection success was over 98%. These results provide preliminary evidence supporting the use of the gyroscope for gait event detection on inclines as well as level walking.
Salim Ghoussayni - One of the best experts on this subject based on the ideXlab platform.
-
Gait event detection on level ground and incline walking using a rate gyroscope
Sensors, 2010Co-Authors: Paola Catalfamo, Salim Ghoussayni, David EwinsAbstract:Gyroscopes have been proposed as sensors for ambulatory gait analysis and functional electrical stimulation systems. Accurate determination of the Initial Contact of the foot with the floor (IC) and the final contact or Foot Off (FO) on different terrains is important. This paper describes the evaluation of a gyroscope placed on the shank for determination of IC and FO in subjects walking outdoors on level ground, and up and down an incline. Performance was compared with a Reference Pressure measurement system. The mean difference between the gyroscope and the Reference was less than –25 ms for IC and less than 75 ms for FO for all terrains. Detection success was over 98%. These results provide preliminary evidence supporting the use of the gyroscope for gait event detection on inclines as well as level walking.