Innovative gait robot for the repetitive practice of floor walking and stair climbing up and down in stroke patients

<p>Abstract</p> <p>Background</p> <p>Stair climbing up and down is an essential part of everyday's mobility. To enable wheelchair-dependent patients the repetitive practice of this task, a novel gait robot, G-EO-Systems (EO, Lat: I walk), based on the end-effector principle, has been designed. The trajectories of the foot plates are freely programmable enabling not only the practice of simulated floor walking but also stair climbing up and down. The article intended to compare lower limb muscle activation patterns of hemiparetic subjects during real floor walking and stairs climbing up, and during the corresponding simulated conditions on the machine, and secondly to demonstrate gait improvement on single case after training on the machine.</p> <p>Methods</p> <p>The muscle activation pattern of seven lower limb muscles of six hemiparetic patients during free and simulated walking on the floor and stair climbing was measured via dynamic electromyography. A non-ambulatory, sub-acute stroke patient additionally trained on the G-EO-Systems every workday for five weeks.</p> <p>Results</p> <p>The muscle activation patterns were comparable during the real and simulated conditions, both on the floor and during stair climbing up. Minor differences, concerning the real and simulated floor walking conditions, were a delayed (prolonged) onset (duration) of the thigh muscle activation on the machine across all subjects. Concerning stair climbing conditions, the shank muscle activation was more phasic and timely correct in selected patients on the device. The severely affected subject regained walking and stair climbing ability.</p> <p>Conclusions</p> <p>The G-EO-Systems is an interesting new option in gait rehabilitation after stroke. The lower limb muscle activation patterns were comparable, a training thus feasible, and the positive case report warrants further clinical studies.</p

Transfer of scientific concepts to clinical practice: recent robot-assisted training studies

Restoration of motor function is a priority of post-stroke rehabilitation, the aim being to facilitate the patient’s reintegration into society. Innovative technologies for neurological rehabilitation must be easy to use and offer patients real benefits, and the treatments they provide must be efficacious and efficient. All these aspects must be carefully evaluated in their development. To achieve restoration of motor function after stroke, task-specific repetitive robot-assisted training of the upper and the lower extremity is currently the most promising approach. The results of clinical trials of robotic devices for upper limb (MIT-Manus, MIME, NeReBot, BiManuTrack, ARMin, ARMOR) and lower limb (LokoHelp, GangTrainer GT1, Haptic Walker, G-EO-Systems, Lokomat) training are here presented with the aim of highlighting the possible gains in motor function due to robotic therapy. Patients who receive robot-assisted training in combination with physiotherapy after stroke are more likely to achieve better motor function than patients trained without these devices, or only with these device

Feasibility and safety of early lower limb robot-assisted training in sub-acute stroke patients: a pilot study

BACKGROUND: So far, the development of robotic devices for the early lower limb mobilization in the sub-acute phase after stroke has received limited attention. AIM: To explore the feasibility of a newly robotic-stationary gait training in sub-acute stroke patients. To report the training effects on lower limb function and muscle activation. DESIGN: A pilot study. SETTING: Rehabilitation ward. METHODS: Two sub-acute stroke inpatients and ten age-matched healthy controls were enrolled. Healthy controls served as normative data. Patients underwent 10 robot-assisted training sessions (20 minutes, 5 days/week) in alternating stepping movements (500 repetitions/session) on a hospital bed in addition to conventional rehabilitation. Feasibility outcome measures were compliance, physiotherapist time, and responses to self-report questionnaires. Efficacy outcomes were bilateral lower limb muscle activation pattern as measured by surface electromyography (sEMG), Motricity Index (MI), Medical Research Council (MRC) grade, and Ashworth Scale (AS) scores before and after training. RESULTS: No adverse events occurred. No significant differences in sEMG activity between patients and healthy controls were observed. Post-training improvement in MI and MRC scores, but no significant changes in AS scores, were recorded. Post- treatment sEMG analysis of muscle activation patterns showed a significant delay in rectus femoris offset (p=0.02) and prolonged duration of biceps femoris (p=0.04) compared to pre-treatment. CONCLUSIONS: The robot-assisted training with our device was feasible and safe. It induced physiological muscle activations pattern in both stroke patients and healthy controls. Full-scale studies are needed to explore its potential role in post-stroke recovery. CLINICAL REHABILITATION IMPACT: This robotic device may enrich early rehabilitation in subacute stroke patients by inducing physiological muscle activation patterns. Future studies are warranted to evaluate its effects on promoting restorative mechanisms involved in lower limb recovery after stroke

Terrestrial Gross Carbon Dioxide Uptake: Global Distribution and Covariation with Climate

Terrestrial gross primary production (GPP) is the largest global CO2 °ux driving several ecosystem functions. We provide an observation- based estimate of this °ux at 123§8 PgCa¡1 using eddy covariance °ux data and various diagnostic models. Tropical forests and sa- vannahs account for 60%. GPP over 40% of the vegetated land is associated with precipitation. State-of-the-art process-oriented bio- sphere models used for climate predictions exhibit a large between- model variation of GPP's latitudinal patterns and show higher spa- tial correlations between GPP and precipitation, suggesting the ex- istence of missing processes or feedback mechanisms which attenu- ate the vegetation response to climate. Our estimates of spatially distributed GPP and its co-variation with climate can help improve coupled climate-carbon cycle process models.JRC.H.2-Air and Climat

Terrestrial gross carbon dioxide uptake: Global distribution and covariation with climate

International audienceTerrestrial gross primary production (GPP) is the largest global CO$_2$ flux driving several ecosystem functions. We provide an observation-based estimate of this flux at 123$\pm$8 petagrams of carbon per year (Pg C year$^{−1}$) using eddy covariance flux data and various diagnostic models. Tropical forests and savannahs account for 60%. GPP over 40% of the vegetated land is associated with precipitation. State-of-the-art process-oriented biosphere models used for climate predictions exhibit a largebetween-model variation of GPP’s latitudinal patterns and show higher spatial correlations between GPP and precipitation, suggesting the existence of missing processes or feedback mechanisms which attenuate the vegetation response to climate. Our estimates of spatially distributed GPP and its covariation with climate can help improve coupled climate–carbon cycle process models

Recent decline in the global land evapotranspiration trend due to limited moisture supply.

More than half of the solar energy absorbed by land surfaces is currently used to evaporate water. Climate change is expected to intensify the hydrological cycle and to alter evapotranspiration, with implications for ecosystem services and feedback to regional and global climate. Evapotranspiration changes may already be under way, but direct observational constraints are lacking at the global scale. Until such evidence is available, changes in the water cycle on land−a key diagnostic criterion of the effects of climate change and variability−remain uncertain. Here we provide a data-driven estimate of global land evapotranspiration from 1982 to 2008, compiled using a global monitoring network, meteorological and remote-sensing observations, and a machine-learning algorithm. In addition, we have assessed evapotranspiration variations over the same time period using an ensemble of process-based land-surface models. Our results suggest that global annual evapotranspiration increased on average by 7.1 ± 1.0 millimetres per year per decade from 1982 to 1997. After that, coincident with the last major El Niño event in 1998, the global evapotranspiration increase seems to have ceased until 2008. This change was driven primarily by moisture limitation in the Southern Hemisphere, particularly Africa and Australia. In these regions, microwave satellite observations indicate that soil moisture decreased from 1998 to 2008. Hence, increasing soil-moisture limitations on evapotranspiration largely explain the recent decline of the global land-evapotranspiration trend. Whether the changing behaviour of evapotranspiration is representative of natural climate variability or reflects a more permanent reorganization of the land water cycle is a key question for earth system science

A recent decline in the global land evaportranspiration trend due to limited moisture supply

LetterInternational audienceMore than half of the solar energy absorbed by land surfaces is currently used to evaporate water. Climate change is expected to intensify the hydrological cycle and to alter evapotranspiration, with implications for ecosystem services and feedback to regional and global climate. Evapotranspiration changes may already be under way, but direct observational constraints are lacking at the global scale. Until such evidence is available, changes in the water cycle on land--a key diagnostic criterion of the effects of climate change and variability-remain uncertain. Here we provide a data-driven estimate of global land evapotranspiration from 1982 to 2008, compiled using a global monitoring network, meteorological and remote-sensing observations, and a machine-learning algorithm. In addition, we have assessed evapotranspiration variations over the same time period using an ensemble of process-based land-surface models. Our results suggest that global annual evapotranspiration increased on average by 7.1 ± 1.0 millimetres per year per decade from 1982 to 1997. After that, coincident with the last major El Niño event in 1998, the global evapotranspiration increase seems to have ceased until 2008. This change was driven primarily by moisture limitation in the Southern Hemisphere, particularly Africa and Australia. In these regions, microwave satellite observations indicate that soil moisture decreased from 1998 to 2008. Hence, increasing soil-moisture limitations on evapotranspiration largely explain the recent decline of the global land-evapotranspiration trend. Whether the changing behaviour of evapotranspiration is representative of natural climate variability or reflects a more permanent reorganization of the land water cycle is a key question for earth system scienc