scholarly journals Control System Design of an Underactuated Dynamic Body Weight Support System Using Its Stability

Sensors ◽  
2021 ◽  
Vol 21 (15) ◽  
pp. 5051
Author(s):  
Grzegorz Gembalczyk ◽  
Piotr Gierlak ◽  
Slawomir Duda
Keyword(s):  
Body Weight ◽  
Control System ◽  
Equations Of Motion ◽  
Experimental Tests ◽  
Body Weight Support ◽  
Essential Property ◽  
Underactuated Mechanical Systems ◽  
Weight Support ◽  
The Stability ◽  
Device Interaction

This paper discusses the stability of systems controlling patient body weight support systems which are used in gait re-education. These devices belong to the class of underactuated mechanical systems. This is due to the application of elastic shock-absorbing connections between the active part of the system and the passive part which impacts the patient. The model takes into account properties of the system, such as inertia, attenuation and susceptibility to the elements. Stability is an essential property of the system due to human–device interaction. In order to demonstrate stability, Lyapunov’s theory of stability, which is based on the model of system dynamics, was applied. The stability of the control system based on a model that requires knowledge of the structure and parameters of the equations of motion was demonstrated. Due to inaccuracies in the modeling of the rope (one of the basic elements of the device), an adaptive control system was introduced and its stability was also proved. The authors conducted simulation and experimental tests that illustrate the functionality of the analyzed control systems.

scholarly journals Modeling and Control of an Underactuated System for Dynamic Body Weight Support

2021 ◽  
Vol 11 (3) ◽  
pp. 905
Author(s):  
Grzegorz Gembalczyk ◽  
Piotr Gierlak ◽  
Slawomir Duda
Keyword(s):  
Body Weight ◽  
Control System ◽  
Support System ◽  
Lyapunov Theory ◽  
Body Weight Support ◽  
Human Gait ◽  
Underactuated System ◽  
Weight Support ◽  
The Stability ◽  
Body Weight Support System

This article concerns the stability analysis of a control system for a dynamic body weight support system in a rehabilitation device for the re-education of human gait. The paper presents a physical model of the device, which characterizes the most important physical phenomena associated with the movement of the system, i.e., inertia, damping, and elasticity. The device has one active and one passive element. They are connected by a connector with elastic and damping properties. This solution provides the kinematic chain required due to interactions with humans, while at the same time ensures that the device is an underactuated system. The article also presents the methodology used to verify the stability of the control system while acting as an active body weight support system. The paper formulates the mathematical model of the system that was used in the synthesis of control using the Lyapunov theory of stability. The results of simulation and experimental tests are also presented.

scholarly journals Dynamic Modeling and Simulation of a Body Weight Support System

2020 ◽  
Vol 2020 ◽  
pp. 1-7
Author(s):  
Zhendong Song ◽  
Wei Chen ◽  
Wenbing Wang ◽  
Guoqing Zhang
Keyword(s):  
Body Weight ◽  
Control Process ◽  
Vertical Motion ◽  
The Body ◽  
Body Weight Support ◽  
Gait Rehabilitation ◽  
Series Elastic Actuator ◽  
Weight Support ◽  
Support Force ◽  
Body Weight Support System

This paper proposes a body weight support (BWS) system with a series elastic actuator (SEA) to facilitate walking assistance and motor relearning during gait rehabilitation. This system comprises the following: a mobile platform that ensures movement of the system on the ground, a BWS mechanism with an SEA that is capable of providing the desired unloading force, and a pelvic brace to smooth the pelvis motions. The control of the body weight support is realized by an active weight-offload method, and a dynamic model of the BWS system with offload mass of a human is conducted to simulate the control process and optimize the parameters. Preliminary results demonstrate that the BWS system can provide the desired support force and vertical motion of the pelvis.

scholarly journals Effect of Uphill Running on VO2, Heart Rate and Lactate Accumulation on Lower Body Positive Pressure Treadmills

Sports ◽  
2021 ◽  
Vol 9 (4) ◽  
pp. 51
Author(s):  
Daniel Fleckenstein ◽  
Olaf Ueberschär ◽  
Jan C. Wüstenfeld ◽  
Peter Rüdrich ◽  
Bernd Wolfarth
Keyword(s):  
Heart Rate ◽  
Body Weight ◽  
Body Weight Support ◽  
Positive Pressure ◽  
Lower Body ◽  
Lactate Accumulation ◽  
Biomechanical Stress ◽  
Lower Body Positive Pressure ◽  
Weight Support ◽  
Body Positive

Lower body positive pressure treadmills (LBPPTs) as a strategy to reduce musculoskeletal load are becoming more common as part of sports conditioning, although the requisite physiological parameters are unclear. To elucidate their role, ten well-trained runners (30.2 ± 3.4 years; VO2max: 60.3 ± 4.2 mL kg−1 min−1) ran at 70% of their individual velocity at VO2max (vVO2max) on a LBPPT at 80% body weight support (80% BWSet) and 90% body weight support (90% BWSet), at 0%, 2% and 7% incline. Oxygen consumption (VO2), heart rate (HR) and blood lactate accumulation (LA) were monitored. It was found that an increase in incline led to increased VO2 values of 6.8 ± 0.8 mL kg−1 min−1 (0% vs. 7%, p < 0.001) and 5.4 ± 0.8 mL kg−1 min−1 (2% vs. 7%, p < 0.001). Between 80% BWSet and 90% BWSet, there were VO2 differences of 3.3 ± 0.2 mL kg−1 min−1 (p < 0.001). HR increased with incline by 12 ± 2 bpm (0% vs. 7%, p < 0.05) and 10 ± 2 bpm (2% vs. 7%, p < 0.05). From 80% BWSet to 90% BWSet, HR increases of 6 ± 1 bpm (p < 0.001) were observed. Additionally, LA values showed differences of 0.10 ± 0.02 mmol l−1 between 80% BWSet and 90% BWSet. Those results suggest that on a LBPPT, a 2% incline (at 70% vVO2max) is not yet sufficient to produce significant physiological changes in VO2, HR and LA—as opposed to running on conventional treadmills, where significant changes are measured. However, a 7% incline increases VO2 and HR significantly. Bringing together physiological and biomechanical factors from previous studies into this practical context, it appears that a 7% incline (at 80% BWSet) may be used to keep VO2 and HR load unchanged as compared to unsupported running, while biomechanical stress is substantially reduced.

Prosthesis Design for Bilateral Hip Disarticulation Management

2014 ◽  
Vol 664 ◽  
pp. 423-428
Author(s):  
Mauricio Plaza Torres ◽  
William Aperador
Keyword(s):  
Body Weight ◽  
Lower Extremity ◽  
Hip Joint ◽  
Joint Capsule ◽  
The Body ◽  
Body Weight Support ◽  
Patient Mobility ◽  
Weight Support ◽  
Crush Injuries ◽  
High Level

Hip disarticulation is an amputation through the hip joint capsule, removing the entire lower extremity, with closure of the remaining musculature over the exposed acetabulum. Tumors of the distal and proximal femur were treated by total femur resection; a hip disarticulation sometimes is performance for massive trauma with crush injuries to the lower extremity. This article discusses the design a system for rehabilitation of a patient with bilateral hip disarticulations. The prosthetics designed allowed the patient to do natural gait suspended between parallel articulate crutches with the body weight support between the crutches. The care of this patient was a challenge due to bilateral amputations at such a high level and the special needs of a patient mobility.

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