Quantitative Analysis of EEG Power Spectrum and EMG Median Power Frequency Changes after Continuous Passive Motion Mirror Therapy System

Abstract

Robotic mirror therapy (MT), which allows movement of the affected limb, is proposed as a more effective method than conventional MT (CMT). To improve the rehabilitation effectiveness of post-stroke patients, we developed a sensory stimulation-based continuous passive motion (CPM)-MT system with two different operating protocols, that is, asynchronous and synchronous modes. To evaluate their effectiveness, we measured brain activation through relative and absolute power spectral density (PSD) changes of electroencephalogram (EEG) mu rhythm in three cases with CMT and CPM-MT with asynchronous and synchronous modes. We also monitored changes in muscle fatigue, which is one of the negative effects of the CPM device, based on median power frequency (MPF) and root mean square (RMS). Relative PSD was most suppressed when subjects used the CPM-MT system under synchronous control: 22.11%, 15.31%, and 16.48% on Cz, C3, and C4, respectively. The absolute average changes in MPF and RMS were 1.59% and 9.78%, respectively, with CPM-MT. Synchronous mode CPM-MT is the most effective method for brain activation, and muscle fatigue caused by the CPM-MT system was negligible. This study suggests the more effective combination rehabilitation system for MT by utilizing CPM and magnetic-based MT task to add action execution and sensory stimulation compared with CMT. method uses voluntary exercise to improve a patient's motivation to rehabilitate [4] and prevents the deterioration of the motor ability of the lesioned brain hemisphere using a visual illusion that bilateral movement has been accomplished [5,6]. However, a major drawback of conventional MT (CMT) is that the paralyzed arm does not move at all during the treatment. Thus, muscle atrophy can be aggravated and the elbow can become stiff. Spasticity and hypertonus are likely to limit the functional use of the paralyzed limb. Additionally, muscle hyperexcitability may lead to secondary complications including contracture, pain, and reduced range of motion. In the long term, these complications may also result in structural changes in connective tissues and muscle fibers [7,8]. In such situations, patients lose their motivation to rehabilitate. In addition, the prevalence of strokes increases in an aging society, and the public healthcare burden of patients who have suffered a stroke increases. The current emphasis on cost reduction in medical services has resulted in reducing the duration of in-patient rehabilitation of post-stroke patients. This results in patients terminating treatment with incomplete recovery. These situations have triggered research on better and cost-efficient methods of treatment for post-stroke patients.To overcome the current limitations of CMT methods, a robotic system that actually moves the affected limb has recently been proposed as an emerging rehabilitative method [9,10]. However, building a new system for only one rehabilitation method, like MT, is difficult to introduce in many hospitals owing to budget and utilization issues. In addition, intro...

Combined Use of EMG and EEG Techniques for Neuromotor Assessment in Rehabilitative Applications: A Systematic Review

“…The distribution of papers in the categories is shown in a pie chart in Figure 4. Study of the cortico-muscular coupling (1) during motor tasks [37][38][39][40][41] and (2) with electrical stimulation [42][43][44][45][46] Investigation of the effects of exoskeleton on functional connectivity [47][48][49] Investigation of the effects of visual feedback [50,51] Detection of movement intention [52,53] Study of the interhemispheric interaction with TMS [54] Study of a neurophysiological marker of stress [55] Study of slow cortical potentials in stroke [56] Study of correlation between lower back pain and altered postural stabilization [57] Test new rehabilitation paradigm [34,[58][59][60][61][62] Investigation of the efficacy of BMI [63] and EEG feedback [64] Table 1. Type of study and aim.…”

“…Test new rehabilitation paradigm [34,[58][59][60][61][62] Investigation of the efficacy of BMI [63] and EEG feedback [64] Study of movement classification combining EEG and EMG [65] Investigation of movement intention [66,67] and motor imagery detection [68] Study of the cortico-muscular coupling [69][70][71] Study of the neuroplasticity with electrical stimulation [72] Investigation of engagement in game rehabilitation [73] Study of the effects of the use of VR in facial rehabilitation [74] Randomized controlled trial Study the effects of transcranial [75,76] and peripheral electrical stimulation [77][78][79] Investigation of the efficacy of lower limb exoskeleton rehabilitation [80] Assessment of a novel gait training paradigm [81] Investigation of the efficacy of neurologic therapy based on music [82] Investigation of the effects of biofeedback [83] Methodological study Presentation of a multivariate approach for motor assessment [32,33] Presentation of a method for compressing EEG-EMG signal [84] Presentation of algorithms for motion detection [85,86] and motion classification [87,88] A total of 21 papers out of 55 (37%) presented observational studies in which functional parameters or effects of treatments were investigated on healthy subjects and patients. An aim commonly found in these works was the assessment of the cortico-muscular coupling during movements [37][38][39]…”

“…A total of 18 out of 55 papers (33%) were classified as pilot studies. Many of these studies presented novel rehabilitation paradigms based on robotics [58][59][60] or exoskeletons [34,61,62]. Donati et al [63] tested a multi-stage brain-machine interface (BMI), while Hashimoto et al [64] used the EEG feedback for improving rehabilitation.…”

“…Mirror visual feedback [50] Wrist movements [69,84]; wrist movements + visual feedback [73] Elbow movements [38]; elbow movements + visual feedback [65] Arm movements [37,57,70,71,87,88]; arm movements + auditory feedback [82]; arm movements + balance handle [52] Hand movements [40,67,83,86]; hand movements + motor imagery + auditory/smelling stimulus [85]; hand movements + audiovisual feedback [56]; hand movements + biofeedback [64] Leg movements [53] Motor imagery swallow and tongue protrusion [68] Respiratory movements [55] Oculus rift [74] Robotic assistance Exoskeleton lower limb + virtual reality [34]; exoskeleton lower limb + virtual reality + BMI [63]; exoskeleton lower limb + walking [47,48,80]; exoskeleton lower limb + treadmill [49] Robotic end effector upper limb [32,33,58,59] Robotic mirror therapy upper limb [60] Hand mobilizer exoskeleton [39,61,62]; hand mobilizer exoskeleton + motor imagery [66] Ankle mobilizer [41] Peripheral electrical stimulation FES + hand movements [43...…”

“…In the selected papers, exoskeletons for upper limbs were designed for hand mobilization and finger move-ments [39,61,62,66]. Four papers [32,33,58,59] presented a robotic end effector for the upper limb, and Park et al [60] developed a robotic mirror therapy for the arm.…”