The Experts below are selected from a list of 321 Experts worldwide ranked by ideXlab platform

Robert D Gregg - One of the best experts on this subject based on the ideXlab platform.

  • underactuated potential energy shaping with contact constraints application to a Powered knee ankle Orthosis
    IEEE Transactions on Control Systems and Technology, 2018
    Co-Authors: Ge Lv, Robert D Gregg
    Abstract:

    Body-weight support (i.e., gravity compensation) is an effective clinical tool for gait rehabilitation after neurological impairment. Body-weight supported training systems have been developed to help patients regain mobility and confidence during walking, but conventional systems constrain the patient’s treatment in clinical environments. We propose that this challenge could be addressed by virtually providing patients with body-weight support through the actuators of a Powered Orthosis (or exoskeleton) utilizing potential energy-shaping control. However, the changing contact conditions and the degrees of underactuation encountered during human walking present significant challenges to consistently matching a desired potential energy for the human in closed loop. We therefore derive a generalized matching condition for shaping Lagrangian systems with holonomic contact constraints. By satisfying this matching condition for four phases of gait, we derive passivity-based control laws to achieve virtual body-weight support through a Powered knee-ankle Orthosis. We demonstrate the beneficial effects of virtual body-weight support in simulations of a human-like biped model, indicating the potential clinical value of this proposed control approach.

  • ICRA - Design and validation of a torque dense, highly backdrivable Powered knee-ankle Orthosis
    IEEE International Conference on Robotics and Automation : ICRA : [proceedings]. IEEE International Conference on Robotics and Automation, 2017
    Co-Authors: Hanqi Zhu, Jack Doan, Calvin Stence, Toby Elery, Robert D Gregg
    Abstract:

    This paper presents the mechatronic design and experimental validation of a novel Powered knee-ankle Orthosis for testing torque-driven rehabilitation control strategies. The modular actuator of the Orthosis is designed with a torque dense motor and a custom low-ratio transmission (24:1) to provide mechanical transparency to the user, allowing them to actively contribute to their joint kinematics during gait training. The 4.88 kg Orthosis utilizes frameless components and light materials, such as aluminum alloy and carbon fiber, to reduce its mass. A human subject experiment demonstrates accurate torque control with high output torque during stance and low backdrive torque during swing at fast walking speeds. This work shows that backdrivability, precise torque control, high torque output, and light weight can be achieved in a Powered Orthosis without the high cost and complexity of variable transmissions, clutches, and/or series elastic components.

  • CDC - Orthotic body-weight support through underactuated potential energy shaping with contact constraints
    Proceedings of the ... IEEE Conference on Decision & Control. IEEE Conference on Decision & Control, 2015
    Co-Authors: Robert D Gregg
    Abstract:

    Body-weight support is an effective clinical tool for gait rehabilitation after neurological impairment. Body-weight supported training systems have been developed to help patients regain mobility and confidence during walking, but conventional systems constrain the patient's treatment in clinical environments. We propose that this challenge could be addressed by virtually providing patients with body-weight support through the actuators of a Powered Orthosis (or exoskeleton) utilizing potential energy shaping control. However, the changing contact conditions and degrees of underactuation encountered during human walking present significant challenges to consistently matching a desired potential energy for the human in closed loop. We therefore introduce a generalized matching condition for shaping Lagrangian systems with holonomic contact constraints. By satisfying this matching condition for four phases of gait, we derive control laws to achieve virtual body-weight support through a Powered knee-ankle Orthosis. We demonstrate beneficial effects of virtual body-weight support in simulations of a human-like biped model, indicating the potential clinical value of this proposed control approach.

Jong Ho Choi - One of the best experts on this subject based on the ideXlab platform.

  • Effect of Pneumatic Compressing Powered Orthosis in Stroke Patients: Preliminary Study
    Annals of rehabilitation medicine, 2015
    Co-Authors: Eun Sil Kim, Yongsoon Yoon, Min Kyun Sohn, Soo Hyun Kwak, Jong Ho Choi
    Abstract:

    Objective To evaluate the feasibility and effectiveness of a knee-ankle-foot Orthosis Powered by artificial pneumatic muscles (PKAFO). Methods Twenty-three hemiplegic patients (age, 59.6±13.7 years) were assessed 19.7±36.6 months after brain lesion. The 10-m walking time was measured as a gait parameter while the individual walked on a treadmill. Walking speed (m/s), step cycle (cycle/s), and step length (m) were also measured on a treadmill with and without PKAFO, and before and after gait training. Clinical parameters measured before and after gait training included Korean version of Modified Bathel Index (K-MBI), manual muscle test (MMT), and Modified Ashworth Scale (MAS) of hemiplegic ankle. Gait training comprised treadmill walking for 20 minutes, 5 days a week for 3 weeks at a comfortable speed. Results The 10-m walking time, walking speed, step length, and step cycle were significantly greater with PKAFO than without PKAFO, and after gait training (both p

  • effect of pneumatic compressing Powered Orthosis in stroke patients preliminary study
    Annals of Rehabilitation Medicine, 2015
    Co-Authors: Eun Sil Kim, Yongsoon Yoon, Min Kyun Sohn, Soo Hyun Kwak, Jong Ho Choi
    Abstract:

    Objective To evaluate the feasibility and effectiveness of a knee-ankle-foot Orthosis Powered by artificial pneumatic muscles (PKAFO). Methods Twenty-three hemiplegic patients (age, 59.6±13.7 years) were assessed 19.7±36.6 months after brain lesion. The 10-m walking time was measured as a gait parameter while the individual walked on a treadmill. Walking speed (m/s), step cycle (cycle/s), and step length (m) were also measured on a treadmill with and without PKAFO, and before and after gait training. Clinical parameters measured before and after gait training included Korean version of Modified Bathel Index (K-MBI), manual muscle test (MMT), and Modified Ashworth Scale (MAS) of hemiplegic ankle. Gait training comprised treadmill walking for 20 minutes, 5 days a week for 3 weeks at a comfortable speed. Results The 10-m walking time, walking speed, step length, and step cycle were significantly greater with PKAFO than without PKAFO, and after gait training (both p<0.05). K-MBI was improved after gait training (p<0.05), but MMT and MAS were not. Conclusion PKAFO may improve gait function in hemiplegic patients. It can be a useful Orthosis for gait training in hemiplegic patients.

Ge Lv - One of the best experts on this subject based on the ideXlab platform.

  • underactuated potential energy shaping with contact constraints application to a Powered knee ankle Orthosis
    IEEE Transactions on Control Systems and Technology, 2018
    Co-Authors: Ge Lv, Robert D Gregg
    Abstract:

    Body-weight support (i.e., gravity compensation) is an effective clinical tool for gait rehabilitation after neurological impairment. Body-weight supported training systems have been developed to help patients regain mobility and confidence during walking, but conventional systems constrain the patient’s treatment in clinical environments. We propose that this challenge could be addressed by virtually providing patients with body-weight support through the actuators of a Powered Orthosis (or exoskeleton) utilizing potential energy-shaping control. However, the changing contact conditions and the degrees of underactuation encountered during human walking present significant challenges to consistently matching a desired potential energy for the human in closed loop. We therefore derive a generalized matching condition for shaping Lagrangian systems with holonomic contact constraints. By satisfying this matching condition for four phases of gait, we derive passivity-based control laws to achieve virtual body-weight support through a Powered knee-ankle Orthosis. We demonstrate the beneficial effects of virtual body-weight support in simulations of a human-like biped model, indicating the potential clinical value of this proposed control approach.

  • Design and validation of a torque dense, highly backdrivable Powered knee-ankle Orthosis
    Proceedings - IEEE International Conference on Robotics and Automation, 2017
    Co-Authors: Hanqi Zhu, Jack Doan, Calvin Stence, Toby Elery, Ge Lv, R Gregg
    Abstract:

    This paper presents the mechatronic design and experimental validation of a novel Powered knee-ankle Orthosis for testing torque-driven rehabilitation control strategies. The modular actuator of the Orthosis is designed with a torque dense motor and a custom low-ratio transmission (24:1) to provide mechanical transparency to the user, allowing them to actively contribute to their joint kinematics during gait training. The 4.88 kg Orthosis utilizes frameless components and light materials, such as aluminum alloy and carbon fiber, to reduce its mass. A human subject experiment demonstrates accurate torque control with high output torque during stance and low backdrive torque during swing at fast walking speeds. This work shows that backdrivability, precise torque control, high torque output, and light weight can be achieved in a Powered Orthosis without the high cost and complexity of variable transmissions, clutches, and/or series elastic components.

Eun Sil Kim - One of the best experts on this subject based on the ideXlab platform.

  • Effect of Pneumatic Compressing Powered Orthosis in Stroke Patients: Preliminary Study
    Annals of rehabilitation medicine, 2015
    Co-Authors: Eun Sil Kim, Yongsoon Yoon, Min Kyun Sohn, Soo Hyun Kwak, Jong Ho Choi
    Abstract:

    Objective To evaluate the feasibility and effectiveness of a knee-ankle-foot Orthosis Powered by artificial pneumatic muscles (PKAFO). Methods Twenty-three hemiplegic patients (age, 59.6±13.7 years) were assessed 19.7±36.6 months after brain lesion. The 10-m walking time was measured as a gait parameter while the individual walked on a treadmill. Walking speed (m/s), step cycle (cycle/s), and step length (m) were also measured on a treadmill with and without PKAFO, and before and after gait training. Clinical parameters measured before and after gait training included Korean version of Modified Bathel Index (K-MBI), manual muscle test (MMT), and Modified Ashworth Scale (MAS) of hemiplegic ankle. Gait training comprised treadmill walking for 20 minutes, 5 days a week for 3 weeks at a comfortable speed. Results The 10-m walking time, walking speed, step length, and step cycle were significantly greater with PKAFO than without PKAFO, and after gait training (both p

  • effect of pneumatic compressing Powered Orthosis in stroke patients preliminary study
    Annals of Rehabilitation Medicine, 2015
    Co-Authors: Eun Sil Kim, Yongsoon Yoon, Min Kyun Sohn, Soo Hyun Kwak, Jong Ho Choi
    Abstract:

    Objective To evaluate the feasibility and effectiveness of a knee-ankle-foot Orthosis Powered by artificial pneumatic muscles (PKAFO). Methods Twenty-three hemiplegic patients (age, 59.6±13.7 years) were assessed 19.7±36.6 months after brain lesion. The 10-m walking time was measured as a gait parameter while the individual walked on a treadmill. Walking speed (m/s), step cycle (cycle/s), and step length (m) were also measured on a treadmill with and without PKAFO, and before and after gait training. Clinical parameters measured before and after gait training included Korean version of Modified Bathel Index (K-MBI), manual muscle test (MMT), and Modified Ashworth Scale (MAS) of hemiplegic ankle. Gait training comprised treadmill walking for 20 minutes, 5 days a week for 3 weeks at a comfortable speed. Results The 10-m walking time, walking speed, step length, and step cycle were significantly greater with PKAFO than without PKAFO, and after gait training (both p<0.05). K-MBI was improved after gait training (p<0.05), but MMT and MAS were not. Conclusion PKAFO may improve gait function in hemiplegic patients. It can be a useful Orthosis for gait training in hemiplegic patients.

K Ohnishi - One of the best experts on this subject based on the ideXlab platform.

  • Powered Orthosis and attachable power assist device with hydraulic bilateral servo system
    International Conference of the IEEE Engineering in Medicine and Biology Society, 2013
    Co-Authors: K Ohnishi, Y Saito, Toru Oshima, Takanori Higashihara
    Abstract:

    This paper discusses the developments and control strategies of exoskeleton-type robot systems for the application of an upper limb Powered Orthosis and an attachable power-assist device for care-givers. Hydraulic Bilateral Servo System, which consist of a computer controlled motor, parallel connected hydraulic actuators, position sensors, and pressure sensors, are installed in the system to derive the joint motion of the exoskeleton arm. The types of hydraulic component structure and the control strategy are discussed in relation to the design philosophy and target joints motions.

  • EMBC - Powered Orthosis and attachable power-assist device with Hydraulic Bilateral Servo System
    Annual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE Engineering in Medicine and Biology Society. Annual Inte, 2013
    Co-Authors: K Ohnishi, Y Saito, Toru Oshima, Takanori Higashihara
    Abstract:

    This paper discusses the developments and control strategies of exoskeleton-type robot systems for the application of an upper limb Powered Orthosis and an attachable power-assist device for care-givers. Hydraulic Bilateral Servo System, which consist of a computer controlled motor, parallel connected hydraulic actuators, position sensors, and pressure sensors, are installed in the system to derive the joint motion of the exoskeleton arm. The types of hydraulic component structure and the control strategy are discussed in relation to the design philosophy and target joints motions.

  • development of hydraulic bilateral servo actuator for Powered Orthosis
    Systems Man and Cybernetics, 2000
    Co-Authors: S Imai, Y Saito, T Tajima, K Ohnishi
    Abstract:

    The development of a machine that supports the movement of the upper limbs has not proceeded for paraplegics. This is because a large output power is necessary in order to move a robot arm while supporting the paralysed body. We propose a new actuator system, called the Hydraulic Bilateral-Servo Actuator (HBSA) system, which has been developed in our laboratory to be applied to Powered Orthosis with seven degrees of freedom.

  • SMC - Development of hydraulic bilateral-servo actuator for Powered Orthosis
    SMC 2000 Conference Proceedings. 2000 IEEE International Conference on Systems Man and Cybernetics. 'Cybernetics Evolving to Systems Humans Organizati, 1
    Co-Authors: S Imai, Y Saito, T Tajima, K Ohnishi
    Abstract:

    The development of a machine that supports the movement of the upper limbs has not proceeded for paraplegics. This is because a large output power is necessary in order to move a robot arm while supporting the paralysed body. We propose a new actuator system, called the Hydraulic Bilateral-Servo Actuator (HBSA) system, which has been developed in our laboratory to be applied to Powered Orthosis with seven degrees of freedom.