Adaptive robotic rehabilitation of locomotion: a clinical study in spinally injured individuals

Abstract

Study design: Clinical study on six spinal cord-injured subjects. The performance of two automatic gait-pattern adaptation algorithms for automated treadmill training rehabilitation of locomotion (called DJATA1 and DJATA2) was tested and compared in this study. Objectives: To test the performance of the two algorithms and to evaluate the corresponding patient satisfaction. We also wanted to evaluate the motivation of the patients to train with a fixed gait pattern versus training where they can influence and change the gait pattern (gaitpattern adaptation). Setting: Spinal Cord Injury Center Paracare, Balgrist, Zu¨rich, Switzerland. Methods: The experimental data were collected during six blinded and randomized training trials (comprising three different conditions per algorithm) split into two training sessions per patient. During the experiments, we have recorded the time courses of the six parameters describing the adaptation. Additionally, a special patient questionnaire was developed that allowed us to collect data regarding the quality, perception, speed, and required effort of the adaptation, as well as patients' opinion that addressed their motivation. The achieved adaptation was evaluated based on the time course of adaptation parameters and based on the patient questionnaire. A statistical analysis was made in order to quantify the data and to compare the two algorithms. Results: Significant adaptation of the gait pattern took place. The patients were in most cases able to change the gait pattern to a desired one and have always perceived the adaptation. No statistically significant differences were found between the performances of the two algorithms based on the evaluated data. However, DJATA2 achieved better adaptation scores. All patients preferred treadmill training with gait-pattern adaptation. Conclusion: In the future, the patients would like to train with gait-pattern adaptation. Besides the subjective opinion indicating the choice of this training modality, gait-pattern adaptation also might lead to additional improvement of the rehabilitation of locomotion as it increases and promotes active training.

Human-centered robotics applied to gait training and assessment

“…Three different technical concepts were applied to the Lokomat gait trainer: (1) impedance-control methods that make the Lokomat soft and compliant, (2) adaptive-control methods that adjust the reference trajectory and/or controller to the individual patient, and (3) a motion-reinforcement strategy that supports patientinduced movements. First experimental results on a nondisabled subject and a subject with paralysis show that the idea of patient-cooperative control technically works [9,41,[47][48].…”

“…The patient's legs are moved with highly repeatable predefined hip-and knee-joint trajectories on the basis of a position-control strategy. Hip-and knee-joint torques are determined from force sensors integrated inside the Lokomat [9,41].…”

Locomotor training using a robotic device in patients with subacute spinal cord injury

“…9 To facilitate the delivery of BWSTT in SCI patients, a motorized robotic-driven gait orthosis was developed, 10 which has many advantages over the conventional BWSTT methods including less effort for the physiotherapists, longer duration, more physiological and reproducible gait patterns, and the possibility to measure a patient's performances. Two different commercial robotic devices for locomotor training had been employed in different studies, the Lokomat (Hocoma Inc., Zurich, Switzerland) a treadmillbased walking machine with robotic arms to move the patients' legs, 11 and the 'Gait Trainer' consisting of two footplates whose driven movements simulated stance and swing. 12 Although the gait patterns induced by these motordriven devices have not been characterized and compared, 13 the results of clinical trial with both of these systems were similar.…”

Locomotor training: Experiencing the changing body

“…The principles of training applied in the BWS and treadmill environment also extend to training over ground. Alternative methods for promoting relearning of walking include robotic-assisted LT, which uses a gait-driven orthosis to facilitate stepping [21][22], and functional electrical stimulation (FES)-or functional neuromuscular stimulation (FNS)-assisted LT, which use FES/FNS technology as facilitators [23][24][25][26][27][28]. Unless otherwise specified, we use the term "LT" to denote manually assisted LT and the transfer of skills to walking over ground.…”