Adaptive Hierarchical Control for the Muscle Strength Training of Stroke Survivors in Robot-Aided Upper-Limb Rehabilitation

Abstract

Muscle strength training for stroke patients is of vital importance for helping survivors to progressively restore muscle strength and improve the performance of their activities in daily living (ADL). An adaptive hierarchical therapy control framework which integrates the patient's real biomechanical state estimation with task-performance quantitative evaluation is proposed. Firstly, a high-level progressive resistive supervisory controller is designed to determine the resistive force base for each training session based on the patient's online task-performance evaluation. Then, a low-level adaptive resistive force triggered controller is presented to further regulate the interactive resistive force corresponding to the patient's real-time biomechanical state -characterized by the patient's bio-damping and bio-stiffness in the course of one training session, so that the patient is challenged in a moderate but engaging and motivating way. Finally, a therapeutic robot system using a Barrett WAM TM compliant manipulator is set up. We recruited eighteen inpatient and outpatient stroke participants who were randomly allocated in experimental (robot-aided) and control (conventional physical therapy) groups and enrolled for sixteen weeks of progressive resistance training. The preliminary results show that the proposed therapy control strategies can enhance the recovery of strength and motor control ability.

Effectiveness of robot therapy on body function and structure in people with limited upper limb function: A systematic review and meta-analysis

“…On average, RT sessions occurred three times per week with a total duration of treatment of 8 weeks. For some studies, primarily those comparing RT to minimal intervention, detailed information on the dose and duration of the intervention was not available[ 35 , 36 , 48 , 54 , 56 ].…”

“…Twenty-one studies evaluated strength using six different instruments. Of these 21 studies, seven (33.3%)[ 15 , 21 , 39 , 40 , 46 , 51 , 58 ] used the Medical Research Council (MRC), three (14.2%)[ 41 , 43 , 49 ] used the hand-held dynamometer, six (28.5%)[ 17 , 20 , 25 , 35 , 54 , 55 ] used the Motor Power Scale (MP), two (9.5%) used the Manual Muscle Testing (MMT)[ 16 , 18 ] and the WAM control program[ 56 , 57 ], and one study[ 51 ] used the Motricity Index (MI). To homogenize the data, Newton and kilogram-force values were converted into pounds.…”

“…Six studies evaluated pain using three different instruments. Of these 6 studies, three studies (50%)[ 16 , 18 , 26 ] used the Visual Analogue Scale (VAS), two studies (33.3%)[ 25 , 56 ] used the Pain Scale of Fugl-Meyer, and one study[ 34 ] used the Chedoke McMaster Stroke Assessment Pain Inventory Scale.…”

A novel approach for robot-assisted upper-limb rehabilitation

“…Fuzzy-based hierarchical supervisory control strategies are also presented in our previous studies. 12,13 Especially in the study, 13 a high-level safety supervisory controller is designed to monitor spasticity-related issues. Great improvements have been made in the current hierarchical supervisory control architecture for incorporating therapists' behavior-decision experiences.…”

Active Elbow Orthosis

“…For an introduction to the field see [1]. Most research is focused on gait rehabilitation of patients with gait dysfunction [2], general lower-limb pathology [3] and stroke survivors, with emphasis equally distributed between lower-limb (see extended references review in [4]) and upper-limb rehabilitation [5][6][7]. Improvement of shoulder-joint integrity using continuous passive motion is illustrated in [8].…”