Real-time biofeedback device for gait rehabilitation of post-stroke patients

In this work, we develop a device, called ‘Walk-Even’, that can provide real-time feedback to correct gait asymmetry commonly exhibited in post-stroke survivors and persons with certain neurological disorders. The device computes gait parameters, including gait time, swing time, and stance time of each leg, to detect gait asymmetry and provide corresponding real-time biofeedback by means of auditory and electrotactile stimulation to actively correct the user's gait. The system consists of customized force-sensor-embedded insoles adjustable to fit any shoe size, electrotactile and auditory feedback circuits, microcontroller, and wireless XBee transceivers. The device also offers data saving capability. To validate its accuracy and reliability, we compared the gait measurements from our device with a commercial gait and balance assessment device, Zeno Walkway. The results show good correlation and agreement in a validity study with six healthy subjects and reliability study with seventeen healthy subjects. In addition, preliminary testing on six post-stroke patients after an 8-week training shows that the Walk-Even device helps to improve gait symmetry, foot pressure and forefoot loading of the affected side. Thus, initial testing indicates that the device is accurate in measuring the gait parameters and effective in improving gait symmetry using real-time feedback. The device is portable and low cost and has the potential for use in a non-clinical setting for patients that can walk independently without assistance. A more extensive testing with stroke patients is still ongoing.

Gait asymmetry and balance in hemiplegic stroke survivors / 中华物理医学与康复杂志

Objective To explore any correlation between gait asymmetry and the balance of hemiplegic stroke survivors.Methods Thirty patients with hemiplegia caused by stroke but who could walk more than 10 metres independently were recruited as the experimental group; 30 age-matched healthy elderly people served as the control group.An AL-600 gait analyzer was used to quantify the spatial and temporal gait parameters of all subjects.Gait asymmetry ratios were calculated.The 30 stroke patients were also assessed with the Berg balance scale (BBS).Two independent sample t-tests were used to compare the step length asymmetry (SLA),swing time asymmetry (SWTA) and STA (stance time asymmetry) ratios for the two groups and their average step widths.Pearson correlation coefficients were calculated relating the SLA,SWTA,STA,step width and BBS results.Results Among the experimental group,swing time and step length on the affected side were significantly different from the unaffected side,and stance time on the affected side was significantly shorter.The control group showed no such significant differences.All of the experimental group's average asymmetry ratios were significantly greater than those of the control group,as was their step width.Step width and BBS score were negative correlated,but step width was positively correlated with the step length and swing time asymmetry ratios.BBS scores were negatively correlated with the step length and swing time asymmetry ratios.Stance time asymmetry and step width showed no significant correlation with the BBS scores.Conclusion The gait of hemiplegic stroke patients is both spatially and temporally asymmetric,and a certain correlation exists between the degree of asymmetry and balance function.