The Sit-to-Stand （STS） is an activity most people perform numerous times daily. Standing up deals with the transition from two stabilized postures, namely seated to standing, with movement of all body segments excep...The Sit-to-Stand （STS） is an activity most people perform numerous times daily. Standing up deals with the transition from two stabilized postures, namely seated to standing, with movement of all body segments except the feet. During the STS the body＇s Center of Gravity （COG） is moved upward from a sitting position to a standing position without losing balance and requiring a good coordination of many muscles. Three main phases of the STS movement can be recognized. One begins to stand up by inclining the upper body forward, which moves body mass toward the feet in order to maintain balance after lift-off. Prior to leaving the chair, hip and knee extensor muscles are activated to provide antigravity support for these joints, this action is commonly referred to as ＂weight shift＂. Finally; after leaving the chair, the leg and trunk joints are straightened to achieve upright stance. The STS task can be considered of major importance for impaired and elderly people to achieve minimal mo- bility and independence. In this paper we detail a procedure for the design of assisting devices to be used for the STS. In par- ticular, an experimental procedure is described firstly to track and record point trajectories and the orientation of the trunk during the STS. This analysis is then used to get information for the design of assisting devices. A proposal and simulation results are presented for a novel mechatronic system. In particular, for the case under study experimental tests are used to drive the actua- tion system for the reported simulation. A functional mechatronic scheme is then proposed to control the device during its operation.展开更多
Standing up refers to the transition from the seating to the standing postures to perform a movement that involves several body segments and requires both voluntary action and equilibrium control during an important d...Standing up refers to the transition from the seating to the standing postures to perform a movement that involves several body segments and requires both voluntary action and equilibrium control during an important displacement of the body Centre of Gravity （COG）. This task can be considered very important for people with reduced mobility to achieve minimal independence in Activity of Daily Living （ADL）. In this paper, we propose solutions for the homecare of persons with reduced mobility, describing a functional design to customize assisting devices for the Sit-to-Stand （STS）. In particular, the support mechanism that generates the requested motion and sustains the body of a person can be synthesized ad-hoc according to the experimental data of the subject. Experimental tests carried out during the Sit-To-Stand are used to track and record point trajectories and the orientation of the trunk of an individual, and they are used to design a 1-DOF mechanism able to reproduce the assigned rigid-body motion. A four-bar linkage has been synthesized according to the desired features. Simulation results are reported to illustrate the engineering soundness of the proposed mechatronic solution.展开更多
Adaptive Neuro-fuzzy Inference System (ANFIS) controller was designed to control knee joint during sit to stand movement through electrical stimuli to quadriceps muscles. The developed ANFIS works as an inverse model ...Adaptive Neuro-fuzzy Inference System (ANFIS) controller was designed to control knee joint during sit to stand movement through electrical stimuli to quadriceps muscles. The developed ANFIS works as an inverse model to the system (functional electrical stimulation (FES)-induced quadriceps-lower leg system), while there is a proportional-integral-derivative (PID) controller in the feedback control. They were designated as ANFIS-PID controller. To evaluate the ANFIS-PID controller, two controllers were developed: open loop and feedback controllers. The results showed that ANFIS-PID controller not only succeeded in controlling knee joint motion during sit to stand movement, but also reduced the deviations between desired trajectory and actual knee movement to ±5°. Promising simulation results provide the potential for feasible clinical application in the future.展开更多
Background： The occurrence of aspen trees increases the conservation value of mature conifer dominated forests. Aspens typically occur as scattered individuals among major tree species, and therefore the inventory of...Background： The occurrence of aspen trees increases the conservation value of mature conifer dominated forests. Aspens typically occur as scattered individuals among major tree species, and therefore the inventory of aspens is challenging. Methods： We characterized aspen populations in a boreal nature reserve using diameter distribution, spatial pattern, and forest attributes： volume, number of aspens, number of large aspen stems and basal area median diameter. The data were collected from three separate forest stands in Koli National Park, eastern Finland. At each site, we measured breast height diameter and coordinates of each aspen. The comparison of inventory methods of aspens within the three stands was based on simulations with mapped field data. We mimicked stand level inventory by locating varying numbers of fixed area circular plots both systematically and randomly within the stands. Additionally, we also tested if the use of airborne laser scanning （ALS） data as auxiliary information would improve the accuracy of the stand level inventory by applying the probability proportional to size sampling to assist the selection of field plot locations. Results： The results showed that aspens were always clustered, and the diameter distributions indicated different stand structures in the three investigated forest stands. The reliability of the volume and number of large aspen trees varied from relative root mean square error figures above 50% with fewer sample plots （5-10） to values of 25%-50% with ]0 or more sample plots. Stand level inventory estimates were also able to detect spatial pattern and the shape of the diameter distribution. In addition, ALS-based auxiliary information could be useful in guiding the inventories, but caution should be used when applying the ALS-supported inventory technique. Conclusions： This study characterized European aspen populations for the purposes of monitoring and management of boreal conservation areas. Our results suggest that if the number of sample plot展开更多
文摘The Sit-to-Stand （STS） is an activity most people perform numerous times daily. Standing up deals with the transition from two stabilized postures, namely seated to standing, with movement of all body segments except the feet. During the STS the body＇s Center of Gravity （COG） is moved upward from a sitting position to a standing position without losing balance and requiring a good coordination of many muscles. Three main phases of the STS movement can be recognized. One begins to stand up by inclining the upper body forward, which moves body mass toward the feet in order to maintain balance after lift-off. Prior to leaving the chair, hip and knee extensor muscles are activated to provide antigravity support for these joints, this action is commonly referred to as ＂weight shift＂. Finally; after leaving the chair, the leg and trunk joints are straightened to achieve upright stance. The STS task can be considered of major importance for impaired and elderly people to achieve minimal mo- bility and independence. In this paper we detail a procedure for the design of assisting devices to be used for the STS. In par- ticular, an experimental procedure is described firstly to track and record point trajectories and the orientation of the trunk during the STS. This analysis is then used to get information for the design of assisting devices. A proposal and simulation results are presented for a novel mechatronic system. In particular, for the case under study experimental tests are used to drive the actua- tion system for the reported simulation. A functional mechatronic scheme is then proposed to control the device during its operation.
文摘Standing up refers to the transition from the seating to the standing postures to perform a movement that involves several body segments and requires both voluntary action and equilibrium control during an important displacement of the body Centre of Gravity （COG）. This task can be considered very important for people with reduced mobility to achieve minimal independence in Activity of Daily Living （ADL）. In this paper, we propose solutions for the homecare of persons with reduced mobility, describing a functional design to customize assisting devices for the Sit-to-Stand （STS）. In particular, the support mechanism that generates the requested motion and sustains the body of a person can be synthesized ad-hoc according to the experimental data of the subject. Experimental tests carried out during the Sit-To-Stand are used to track and record point trajectories and the orientation of the trunk of an individual, and they are used to design a 1-DOF mechanism able to reproduce the assigned rigid-body motion. A four-bar linkage has been synthesized according to the desired features. Simulation results are reported to illustrate the engineering soundness of the proposed mechatronic solution.
文摘Adaptive Neuro-fuzzy Inference System (ANFIS) controller was designed to control knee joint during sit to stand movement through electrical stimuli to quadriceps muscles. The developed ANFIS works as an inverse model to the system (functional electrical stimulation (FES)-induced quadriceps-lower leg system), while there is a proportional-integral-derivative (PID) controller in the feedback control. They were designated as ANFIS-PID controller. To evaluate the ANFIS-PID controller, two controllers were developed: open loop and feedback controllers. The results showed that ANFIS-PID controller not only succeeded in controlling knee joint motion during sit to stand movement, but also reduced the deviations between desired trajectory and actual knee movement to ±5°. Promising simulation results provide the potential for feasible clinical application in the future.
基金supported by by the strategic funding of the University of Eastern Finland
文摘Background： The occurrence of aspen trees increases the conservation value of mature conifer dominated forests. Aspens typically occur as scattered individuals among major tree species, and therefore the inventory of aspens is challenging. Methods： We characterized aspen populations in a boreal nature reserve using diameter distribution, spatial pattern, and forest attributes： volume, number of aspens, number of large aspen stems and basal area median diameter. The data were collected from three separate forest stands in Koli National Park, eastern Finland. At each site, we measured breast height diameter and coordinates of each aspen. The comparison of inventory methods of aspens within the three stands was based on simulations with mapped field data. We mimicked stand level inventory by locating varying numbers of fixed area circular plots both systematically and randomly within the stands. Additionally, we also tested if the use of airborne laser scanning （ALS） data as auxiliary information would improve the accuracy of the stand level inventory by applying the probability proportional to size sampling to assist the selection of field plot locations. Results： The results showed that aspens were always clustered, and the diameter distributions indicated different stand structures in the three investigated forest stands. The reliability of the volume and number of large aspen trees varied from relative root mean square error figures above 50% with fewer sample plots （5-10） to values of 25%-50% with ]0 or more sample plots. Stand level inventory estimates were also able to detect spatial pattern and the shape of the diameter distribution. In addition, ALS-based auxiliary information could be useful in guiding the inventories, but caution should be used when applying the ALS-supported inventory technique. Conclusions： This study characterized European aspen populations for the purposes of monitoring and management of boreal conservation areas. Our results suggest that if the number of sample plot
