Human-robot interaction torque estimation methods for a lower limb rehabilitation robotic system with uncertainties

Lower limb rehabilitation robot (LLRR) users, to successfully conduct isotonic exercises, require real-time feedback on the torque they exert on the robot to meet the goal of the treatment. Still, direct torque measuring is expensive, and indirect encoder-based estimation strategies, such as inverse dynamics (ID) and Nonlinear Disturbance Observers (NDO), are sensitive to Body Segment Inertial Parameters (BSIPs) uncertainties. We envision a way to minimize such parametric uncertainties. This paper proposes two human–robot interaction torque estimation methods: the Identified ID-based method (IID) and the Identified NDO-based method (INDO). Evaluating in simulation the proposal to apply, in each rehabilitation session, a sequential two-phase method: (1) An initial calibration phase will use an online parameter estimation to reduce sensitivity to BSIPs uncertainties. (2) The torque estimation phase uses the estimated parameters to obtain a better result. We conducted simulations under signal-to-noise ratio (SNR) = 40 dB and 20% BSIPs uncertainties. In addition, we compared the effectiveness with two of the best methods reported in the literature via simulation. Both proposed methods obtained the best Coefficient of Correlation, Mean Absolute Error, and Root Mean Squared Error compared to the benchmarks. Moreover, the IID and INDO fulfilled more than 72.2% and 88.9% of the requirements, respectively. In contrast, both methods reported in the literature only accomplish 27.8% and 33.3% of the requirements when using simulations under noise and BSIPs uncertainties. Therefore, this paper extends two methods reported in the literature and copes with BSIPs uncertainties without using additional sensors

In Vitro and In Vivo Efficacy of Ether Lipid Edelfosine against Leishmania spp. and SbV-Resistant Parasites

Leishmaniasis represents a major international health problem, has a high morbidity and mortality rate, and is classified as an emerging and uncontrolled disease by the World Health Organization. The migration of population from endemic to nonendemic areas, and tourist activities in endemic regions are spreading the disease to new areas. Unfortunately, treatment of leishmaniasis is far from satisfactory, with only a few drugs available that show significant side-effects. Here, we show in vitro and in vivo evidence for the antileishmanial activity of the ether phospholipid edelfosine, being effective against a wide number of Leishmania spp. causing cutaneous, mucocutaneous and visceral leishmaniasis. Our experimental mouse and hamster models demonstrated not only a significant antileishmanial activity of edelfosine oral administration against different wild-type Leishmania spp., but also against parasites resistant to pentavalent antimonials, which constitute the first line of treatment worldwide. In addition, edelfosine exerted a higher antileishmanial activity and a lower proneness to generate drug resistance than miltefosine, the first drug against leishmaniasis that can be administered orally. These data, together with our previous findings, showing an anti-inflammatory action and a very low toxicity profile, suggest that edelfosine is a promising orally administered drug for leishmaniasis, thus warranting clinical evaluation

Evaluation of the seismic risk of the unreinforced masonry building stock in Antioquia, Colombia

This paper presents the development of an exposure model for the residential building stock in Antioquia (the second most populated Department of Colombia), the development of fragility functions for unreinforced masonry buildings, and estimation of building damage for two possible seismic events. Both the exposure and fragility models are publically available and can be used to calculate damage and losses due to single events, or probabilistic seismic hazard. The exposure model includes information regarding the total built-up area, number of buildings and inhabitants, building class, and replacement cost. The methodology used for the creation of the exposure model was based on available cadastral information, survey data, and expert judgment. Fragility functions were derived using nonlinear time history analyses on single-degree-of-freedom oscillators, for unreinforced masonry structures which represent more than 60% of the building stock in the region. Both seismic scenarios indicate that an event corresponding to a return period of 500 years located within the region of interest would cause slight or moderate damage to nearly 95 thousand structures, and about 32 thousand would have severe damage or collapse. This study was developed as part of the South America Risk Assessment project, supported by the Global Earthquake Model and SwissRe Foundation. © 2016, Springer Science+Business Media Dordrecht

The wMel Strain of Wolbachia Reduces Transmission of Chikungunya Virus in Aedes aegypti.

BACKGROUND:New approaches to preventing chikungunya virus (CHIKV) are needed because current methods are limited to controlling mosquito populations, and they have not prevented the invasion of this virus into new locales, nor have they been sufficient to control the virus upon arrival. A promising candidate for arbovirus control and prevention relies on the introduction of the intracellular bacterium Wolbachia into Aedes aegypti mosquitoes. This primarily has been proposed as a tool to control dengue virus (DENV) transmission; however, evidence suggests Wolbachia infections confer protection for Ae. aegypti against CHIKV. Although this approach holds much promise for limiting virus transmission, at present our understanding of the ability of CHIKV to infect, disseminate, and be transmitted by wMel-infected Ae. aegypti currently being used at Wolbachia release sites is limited. METHODOLOGY/PRINCIPAL FINDINGS:Using Ae. aegypti infected with the wMel strain of Wolbachia that are being released in Medellin, Colombia, we report that these mosquitoes have reduced vector competence for CHIKV, even with extremely high viral titers in the bloodmeal. In addition, we examined the dynamics of CHIKV infection over the course of four to seven days post feeding. Wolbachia-infected mosquitoes remained non-infective over the duration of seven days, i.e., no infectious virus was detected in the saliva when exposed to bloodmeals of moderate viremia, but CHIKV-exposed, wild type mosquitoes did have viral loads in the saliva consistent with what has been reported elsewhere. Finally, the presence of wMel infection had no impact on the lifespan of mosquitoes as compared to wild type mosquitoes following CHIKV infection. CONCLUSIONS/SIGNIFICANCE:These results could have an impact on vector control strategies in areas where Ae. aegypti are transmitting both DENV and CHIKV; i.e., they argue for further exploration, both in the laboratory and the field, on the feasibility of expanding this technology beyond DENV

Human-Robot Interaction Torque Estimation Methods for a Lower Limb Rehabilitation Robotic System with Uncertainties

Lower limb rehabilitation robot (LLRR) users, to successfully conduct isotonic exercises, require real-time feedback on the torque they exert on the robot to meet the goal of the treatment. Still, direct torque measuring is expensive, and indirect encoder-based estimation strategies, such as inverse dynamics (ID) and Nonlinear Disturbance Observers (NDO), are sensitive to Body Segment Inertial Parameters (BSIPs) uncertainties. We envision a way to minimize such parametric uncertainties. This paper proposes two human–robot interaction torque estimation methods: the Identified ID-based method (IID) and the Identified NDO-based method (INDO). Evaluating in simulation the proposal to apply, in each rehabilitation session, a sequential two-phase method: (1) An initial calibration phase will use an online parameter estimation to reduce sensitivity to BSIPs uncertainties. (2) The torque estimation phase uses the estimated parameters to obtain a better result. We conducted simulations under signal-to-noise ratio (SNR) = 40 dB and 20% BSIPs uncertainties. In addition, we compared the effectiveness with two of the best methods reported in the literature via simulation. Both proposed methods obtained the best Coefficient of Correlation, Mean Absolute Error, and Root Mean Squared Error compared to the benchmarks. Moreover, the IID and INDO fulfilled more than 72.2% and 88.9% of the requirements, respectively. In contrast, both methods reported in the literature only accomplish 27.8% and 33.3% of the requirements when using simulations under noise and BSIPs uncertainties. Therefore, this paper extends two methods reported in the literature and copes with BSIPs uncertainties without using additional sensors

Viral titers in saliva of WT mosquitoes at different days after peroral infection with 6.90 or 9.00 log₁₀ PFU/ml of CHIKV.

<p>Error bars represent the Bootstrap 95% confidence interval for the mean.</p

Infection dynamics through time for WT (black line) and wMelCOL mosquitoes (gray line) orally infected with 9.00 log₁₀ PFU/ml of CHIKV.

<p>Mosquitoes were examined at days 4–7 to determine infection, dissemination, and transmission efficiencies. Infection efficiency corresponds to the proportion of mosquitoes with virus-infected bodies among the tested ones. Dissemination efficiency corresponds to the proportion of mosquitoes with virus-infected legs, and transmission efficiency corresponds to the proportion of mosquitoes with infectious saliva among those infected. *, significant reduction in infection rates (*<i>p</i><0.05, **<i>p</i><0.01, ***<i>p</i><0.001). <b>A).</b> Percent infected (4d, n = 20 for <i>w</i>MelCOL and n = 18 for WT; 5d, n = 18 for <i>w</i>MelCOl and n = 19 for WT; 6d, n = 19 for <i>w</i>MelCOL and n = 14 for WT; 7d n = 30 for <i>w</i>MelCOL and WT. <b>B).</b> Percent disseminated (of infected). <b>C.)</b> Percent transmitting (of infected).</p

Infection dynamics through time for WT (black line) and <i>w</i>MelCOL mosquitoes (gray line) orally infected with 6.90 log₁₀ PFU/ml of CHIKV.

<p>Mosquitoes were examined at days 4–7 to determine infection, dissemination, and transmission efficiencies. Infection efficiency corresponds to the proportion of mosquitoes with virus-infected bodies among the tested ones. Dissemination efficiency corresponds to the proportion of mosquitoes with virus-infected legs, and transmission efficiency corresponds to the proportion of mosquitoes with infectious saliva among those infected. *, significant reduction in infection rates (*<i>p</i><0.05, **<i>p</i><0.01, ***<i>p</i><0.001). <b>A).</b> Percent infected (4d, n = 20 for <i>w</i>MelCOL and WT; 5d, n = 18 for <i>w</i>MelCOl and n = 19 for WT; 6d, n = 17 for <i>w</i>MelCOL and n = 18 for WT; 7d n = 30 for <i>w</i>MelCOL and WT. <b>B).</b> Percent disseminated (of infected). <b>C.)</b> Percent transmitting (of infected).</p