Improving activity recognition using a wearable barometric pressure sensor in mobility-impaired stroke patients.

© 2015 Massé et al.Background: Stroke survivors often suffer from mobility deficits. Current clinical evaluation methods, including questionnaires and motor function tests, cannot provide an objective measure of the patients mobility in daily life. Physical activity performance in daily-life can be assessed using unobtrusive monitoring, for example with a single sensor module fixed on the trunk. Existing approaches based on inertial sensors have limited performance, particularly in detecting transitions between different activities and postures, due to the inherent inter-patient variability of kinematic patterns. To overcome these limitations, one possibility is to use additional information from a barometric pressure (BP) sensor. Methods: Our study aims at integrating BP and inertial sensor data into an activity classifier in order to improve the activity (sitting, standing, walking, lying) recognition and the corresponding body elevation (during climbing stairs or when taking an elevator). Taking into account the trunk elevation changes during postural transitions (sit-to-stand, stand-to-sit), we devised an event-driven activity classifier based on fuzzy-logic. Data were acquired from 12 stroke patients with impaired mobility, using a trunk-worn inertial and BP sensor. Events, including walking and lying periods and potential postural transitions, were first extracted. These events were then fed into a double-stage hierarchical Fuzzy Inference System (H-FIS). The first stage processed the events to infer activities and the second stage improved activity recognition by applying behavioral constraints. Finally, the body elevation was estimated using a pattern-enhancing algorithm applied on BP. The patients were videotaped for reference. The performance of the algorithm was estimated using the Correct Classification Rate (CCR) and F-score. The BP-based classification approach was benchmarked against a previously-published fuzzy-logic classifier (FIS-IMU) and a conventional epoch-based classifier (EPOCH). Results: The algorithm performance for posture/activity detection, in terms of CCR was 90.4 %, with 3.3 % and 5.6 % improvements against FIS-IMU and EPOCH, respectively. The proposed classifier essentially benefits from a better recognition of standing activity (70.3 % versus 61.5 % [FIS-IMU] and 42.5 % [EPOCH]) with 98.2 % CCR for body elevation estimation. Conclusion: The monitoring and recognition of daily activities in mobility-impaired stoke patients can be significantly improved using a trunk-fixed sensor that integrates BP, inertial sensors, and an event-based activity classifier

Primer registro de hospedador para el parasitoide oófilo, Polynema haitianum (Hymenoptera: Mymaridae), con descripción del macho y redescripción de la hembra

El presente trabajo científico provee la primera asociación hospedador - parasitoide y amplía la distribución geográfica para el parasitoide Polynema haitianum Dozier (Hymenoptera: Mymaridae) a varios paises de Sudamérica, previamente conocido para Haití. Además se describió el macho y se redescribio la hembra. En este trabajo se obtuvo una especie de parasitoides de huevos, Polynema haitianum, la cual se desarrolla en huevos de Xerophloea viridis (Hemiptera: Cicadellidae). Con el registro de P. haitianum se eleva a tres el número de las especies de parasitoides que atacan a la chicharrita X. viridis, en Argentina.Fil: Luft Albarracin, Erica Beatriz. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucuman. Planta Piloto de Procesos Industriales Microbiologicos; ArgentinaFil: Aquino, Daniel A.. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. División Entomología; Argentin

Specialized physiological studies in support of manned space flight

The effects of a diuretic (Lasix) induced dehydration on the cardiovascular and hematological responses to lower body negative pressure (LBNP) were analyzed and compared to previous observations on dehydration following exercise in the heat. During LBNP runs the subjects were monitored for changes in blood volume, heart rate, blood pressure, and variations in the volume of the left calf. It was concluded that Lasix dehydration produced a depletion of the body electrolytes at the expense of both the plasma and extravascular compartments. Striking differences were found between those subjects who were physically active (Runners: R) and those who did not engage in any regular physical activity (Non-runners: NR). Tolerance to LBNP (Torr x min) was significantly lower in the R's than the NR's before and after dehydration, however the R's lost more of their tolerance after dehydration with Lasix than after exercise in the heat for about the same fluid loss. The opposite was true for the NR's. Two factors appear to be responsible for the lower LBNP tolerance in R's: parasympathetic inhibition of cardiac activity during LBNP and a greater propensity to pool blood in the lower extremities

Role of walking-exercise therapy after stroke

Stroke commonly leads to reduced mobility, which leads to deconditioning and a worsening of vascular risk factors, such as diabetes. The worsened risk profile leads to further strokes and disability--a vicious cycle for the stroke survivor. Exercise (walking) therapy may break this cycle by providing adequate stimuli for improving gait through plastic adaptation in the brain and through increasing fitness. Randomized, controlled data demonstrate the efficacy for gains in fitness and walking speed, the latter being related to lasting changes in activation patterns of the brainstem and cerebellum. Diabetes and muscle inflammation can also be improved by aerobic exercise training. The scope of this review summarizes these data and identifies unresolved issues related to optimization, intensity and maintenance of therapy effects. Exercise should be an integral part of every rehabilitation program

Coherent states on the circle

We present a possible construction of coherent states on the unit circle as configuration space. In our approach the phase space is the product Z x S^1. Because of the duality of canonical coordinates and momenta, i.e. the angular variable and the integers, this formulation can also be interpreted as coherent states over an infinite periodic chain. For the construction we use the analogy with our quantization over a finite periodic chain where the phase space was Z_M x Z_M. Properties of the coherent states constructed in this way are studied and the coherent states are shown to satisfy the resolution of unity.Comment: 7 pages, presented at GROUP28 - "28th International Colloquium on Group Theoretical Methods in Physics", Newcastle upon Tyne, July 2010. Accepted in Journal of Physics Conference Serie

The repertory of bone marrow progenitor cells associated with lymphogenic metastasis in patients with invasive carcinoma of no special type

The high mortality of patients with breast cancer is determined by metastatic disease. It is thought that the metastatic disease development associated with the repertory of bone marrow progenitor cells in breast cancer patients. In our study the correlation between the bone marrow progenitor cells presences in the tumor and blood of patients and the lymphogenic metastasis development was studied. The main clinical and pathological parameters of 24 patients with invasive breast carcinoma of non-specific type were analyzed. Endothelial progenitor cells, mesenchymal stem cells, macrophage precursors, hematopoietic progenitor cells were detected with specific antibodies against CD34, CD133, CD90, VEGFR1, CD11b, CD45, CD202 in the cell-rich fluid from frozen tumor. The amount of MCP-1 in the patients blood serum was assessed by enzymelinked immunosorbent assay (ELISA), at a wavelength of 450 nm. The cytokines concentration was calculated from the calibration plot. The program package Statistica 10.0. was used for statistical data processing. The high risk of lymphogenic metastasis in patients who didn't complete a neoadjuvant chemotherapy course was associated with the number of HPC, EPC and MSC in tumor and MCP-1 in blood

Dihedral symmetry of periodic chain: quantization and coherent states

Our previous work on quantum kinematics and coherent states over finite configuration spaces is extended: the configuration space is, as before, the cyclic group Z_n of arbitrary order n=2,3,..., but a larger group - the non-Abelian dihedral group D_n - is taken as its symmetry group. The corresponding group related coherent states are constructed and their overcompleteness proved. Our approach based on geometric symmetry can be used as a kinematic framework for matrix methods in quantum chemistry of ring molecules.Comment: 13 pages; minor changes of the tex

Mononuclear Phagocyte System Depletion Blocks Interstitial Tonicity-Responsive Enhancer Binding Protein/Vascular Endothelial Growth Factor C Expression and Induces Salt-Sensitive Hypertension in Rats

We showed recently that mononuclear phagocyte system (MPS) cells provide a buffering mechanism for salt-sensitive hypertension by driving interstitial lymphangiogenesis, modulating interstitial Na(+) clearance, and increasing endothelial NO synthase protein expression in response to very high dietary salt via a tonicity-responsive enhancer binding protein/vascular endothelial growth factor C regulatory mechanism. We now tested whether isotonic saline and deoxycorticosterone acetate (DOCA)-salt treatment leads to a similar regulatory response in Sprague-Dawley rats. Male rats were fed a low-salt diet and received tap water (low-salt diet LSD), 1.0% saline (high-salt diet HSD), or DOCA+1.0% saline (DOCA-HSD). To test the regulatory role of interstitial MPS cells, we further depleted MPS cells with clodronate liposomes. HSD and DOCA-HSD led to Na(+) accumulation in the skin, MPS-driven tonicity-responsive enhancer binding protein/vascular endothelial growth factor C-mediated hyperplasia of interstitial lymph capillaries, and increased endothelial NO synthase protein expression in skin interstitium. Clodronate liposome MPS cell depletion blocked MPS infiltration in the skin interstitium, resulting in unchanged tonicity-responsive enhance binding protein/vascular endothelial growth factor C levels and absent hyperplasia of the lymph capillary network. Moreover, no increased skin endothelial NO synthase protein expression occurred in either clodronate liposome-treated HSD or DOCA-salt rats. Thus, absence of the MPS-cell regulatory response converted a salt-resistant blood-pressure state to a salt-sensitive state in HSD rats. Furthermore, salt-sensitive hypertension in DOCA-salt rats was aggravated. We conclude that MPS cells act as onsite controllers of interstitial volume and blood pressure homeostasis, providing a local regulatory salt-sensitive tonicity-responsive enhancer binding protein/vascular endothelial growth factor C-mediated mechanism in the skin to maintain normal blood pressure in states of interstitial Na(+) and Cl(-) accumulation. Failure of this physiological extrarenal regulatory mechanism leads to a salt-sensitive blood pressure response