**3.2 Study methodology**

*Assistive and Rehabilitation Engineering*

band power (8–13 Hz) was used to represent a relaxed state, updated every 10 s as a proportion to total power in the 1–35 Hz frequency band. While EMG was sampled

The goal of both the feedforward and feedback is to successfully attempt a movement or physical task while maintaining a relaxed brain-muscle state pre- and post-action comparable to resting state. If effort results in a deviation from resting state, return to resting state post-effort should be immediate. Brain and muscle influence each other too. Losing attention partially or fully may result in loss of ability to imitate the feedforward video and respond to feedback. Incremental changes in self-regulation are presented visually in the real-time user interface, which then

**Figure 4** depicts the user interface on the computer screen. The subject observes the video as the feedforward in order to imitate it with the same speed. The koala bears, and tree serve as agonist and antagonist muscle EMG feedback during such imitation. The subject attempts to activate the appropriate muscle to raise the brown bear (agonist) to the top of the tree while keeping the gray bear (antagonist) as steady and close to the bottom of the tree as possible. The yellow smiley face represents EEG frequency band feedback as a measure of a relaxed brain state which needs to be maintained as best as possible while imitating the video-based physical

In both the clinical studies, the subject tried to imitate an exercise and task practice video sequence running on the computer screen, while attempting to correct maladaptive over-activation and under-activation in opposing muscle pairs displayed on the same screen. Using a slower speed of execution than normal allowed proximal joints of the upper limb to stabilize and reduce temporal demands on the subject [38]. The slow-paced video sequences allowed time to train relaxation between repetitions. Also, the need to achieve a relaxation goal immediately after activation encouraged the subjects not to over-activate the muscles and to moderate their effort. This strategy was found to delay the onset of high dynamic muscle tone and allow for better repetition-based performance based on greater number of successful relaxations. When subjects experienced difficulties in being able to relax their muscles, they intuitively made postural corrections to let go and relax deeper before the next muscle activation. EMG thresholds displayed on the software gave them a clear indication on activation and relaxation targets appropriate for training, which were based on previously calibrated maximum voluntary contraction (targets were up to 40% of maximum) and resting state EMG respectively, for various muscle groups. In this paper, analysis of only the EMG peaks data as seen during activity and immediately post activity repetition is highlighted. The EEG and other

at 1000 samples/sec, EEG was sampled at 256 samples/s.

*SynPhNe learning model platform and user-interface.*

provides an impetus for the patient to self-regulate further.

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movement or task.

**Figure 4.**

In Trial 1, 15 adult chronic stroke subjects with a hemiplegic hand (31–69 years; 4 females, 11 males) were recruited for the study (**Table 1**). In Trial 2, 10 adult


#### **Table 1.**

*Demographic of recruited subjects.*

chronic stroke subjects with a hemiplegic hand (45–69 years; 1 female, 9 males) were recruited for the study (**Table 1**).

Both left and right limb impaired subjects were included for a better patient representation with at least 6 months post a first clinical stroke. Only paralysis with M.R.C. grade between 1 and 3 at elbow and digits was considered for inclusion. Passive, pain-free range of motion was at least 50% in all below elbow joints. No exclusion was made based on type of stroke and the group included those with ataxia and tactile sensory loss.

The experiments had only treatment group whose members had plateaued (those who had completed the rehabilitation program recommended by the hospital) in functional recovery and were ready to discontinue any other form of regular or alternative therapy during the study.

In Trial 1, the subjects were randomized between two clinical therapists, where either of them could conduct any session for any subject (as is common in a typical clinical setting). In Trial 2, to simulate a home-based, non-clinical environment, the therapy was not conducted in a standard hospital therapy/rehabilitation ward but rather in a normal spare room with a table and a chair. A research associate with a non-therapy background was trained to operate the SynPhNe system to deliver the sessions every day.

Each subject completed a 4-week, 3 sessions/week protocol using the automated SynPhNe device which delivers the learning modality. Each session lasted for 50–75 min including the setup time. In Trial 1, the EEG signals were captured during three sessions to track changes, i.e., in the beginning, midway and end of the study whereas in Trial 2, the EEG signals were captured in all 12 sessions, with the smiley face retained as a form of feedback on relaxed brain state represented by the relative alpha-band power as calibrated at rest. This brain-based feedback was introduced after it was observed that a significant component of therapist supervision in Trial 1 consisted of repeatedly nudging the subjects' attention back to task.

#### **Figure 5.**

*Task practice (1) picking up a pen, (2) grasping a bottle, (3) flipping a page, (4) using a pair of chopsticks (pictures extracted from the instructional video created for the experiment).*

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to minimize.

**Figure 6.**

**4. Results and discussions**

*Restoring Independent Living after Disability Using a Wearable Device: A Synergistic…*

Imitating the video, subjects performed four basic hand movements—wrist extension and flexion, finger extension and flexion, pronation and supination, and open grasp. This was followed by four everyday tasks—picking up a pen, flipping a

*Clinical trial setup in (A) Trial 1 (therapy ward) and (B) Trial 2 (outside therapy ward).*

These four tasks were chosen to represent a two-finger pinch with pronation, a cylindrical grasp, a key pinch with pronation and supination and a five-finger pinch which demands attention. Each exercise was repeated five times in the first three sessions and 10 times in the subsequent sessions while attempting to maintain a pre-calibrated agonist-antagonist balance using the biofeedback. In Trial 1, some of the more severely affected subjects (n = 7) were provided the facility for an automated triggering of electrical stimulation on extensor muscles for some or all sessions if the subject achieved an agonist EMG threshold while maintaining a relaxed antagonist [39]. In Trial 2, we did not use any FES as Trial 1 indicated that FES induced exaggerated, instantaneous antagonist-side reactions, which our protocol was, in fact, trying

Pre-, mid-, and post-outcomes were measured using standard clinical scales [Fugl Meyer Upper Extremity Motor assessment (FMA) and Action Research Arm Test (ARAT)] to assess both gross and fine movements [40]. They were also randomized for assessment between two other therapists who were blinded to the study protocol. All subjects provided a signed written consent. Ethics approval was obtained from the Institutional Review Board of National Healthcare Group,

On comparing the muscle activation and relaxation scores across all subjects in Trial 1 (168 sessions) and Trial 2 (total 120 sessions), it was seen that successful

Singapore. The set-up for the two experiments is shown in **Figure 6**.

**4.1 Association of muscle contraction to relaxation**

page, grasping a bottle and use of chopsticks (**Figure 5**).

*DOI: http://dx.doi.org/10.5772/intechopen.86011*

*Restoring Independent Living after Disability Using a Wearable Device: A Synergistic… DOI: http://dx.doi.org/10.5772/intechopen.86011*

#### **Figure 6.**

*Assistive and Rehabilitation Engineering*

ataxia and tactile sensory loss.

sessions every day.

attention back to task.

were recruited for the study (**Table 1**).

or alternative therapy during the study.

chronic stroke subjects with a hemiplegic hand (45–69 years; 1 female, 9 males)

Both left and right limb impaired subjects were included for a better patient representation with at least 6 months post a first clinical stroke. Only paralysis with M.R.C. grade between 1 and 3 at elbow and digits was considered for inclusion. Passive, pain-free range of motion was at least 50% in all below elbow joints. No exclusion was made based on type of stroke and the group included those with

The experiments had only treatment group whose members had plateaued (those who had completed the rehabilitation program recommended by the hospital) in functional recovery and were ready to discontinue any other form of regular

In Trial 1, the subjects were randomized between two clinical therapists, where either of them could conduct any session for any subject (as is common in a typical clinical setting). In Trial 2, to simulate a home-based, non-clinical environment, the therapy was not conducted in a standard hospital therapy/rehabilitation ward but rather in a normal spare room with a table and a chair. A research associate with a non-therapy background was trained to operate the SynPhNe system to deliver the

Each subject completed a 4-week, 3 sessions/week protocol using the automated SynPhNe device which delivers the learning modality. Each session lasted for 50–75 min including the setup time. In Trial 1, the EEG signals were captured during three sessions to track changes, i.e., in the beginning, midway and end of the study whereas in Trial 2, the EEG signals were captured in all 12 sessions, with the smiley face retained as a form of feedback on relaxed brain state represented by the relative alpha-band power as calibrated at rest. This brain-based feedback was introduced after it was observed that a significant component of therapist supervision in Trial 1 consisted of repeatedly nudging the subjects'

*Task practice (1) picking up a pen, (2) grasping a bottle, (3) flipping a page, (4) using a pair of chopsticks* 

*(pictures extracted from the instructional video created for the experiment).*

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**Figure 5.**

*Clinical trial setup in (A) Trial 1 (therapy ward) and (B) Trial 2 (outside therapy ward).*

Imitating the video, subjects performed four basic hand movements—wrist extension and flexion, finger extension and flexion, pronation and supination, and open grasp. This was followed by four everyday tasks—picking up a pen, flipping a page, grasping a bottle and use of chopsticks (**Figure 5**).

These four tasks were chosen to represent a two-finger pinch with pronation, a cylindrical grasp, a key pinch with pronation and supination and a five-finger pinch which demands attention. Each exercise was repeated five times in the first three sessions and 10 times in the subsequent sessions while attempting to maintain a pre-calibrated agonist-antagonist balance using the biofeedback. In Trial 1, some of the more severely affected subjects (n = 7) were provided the facility for an automated triggering of electrical stimulation on extensor muscles for some or all sessions if the subject achieved an agonist EMG threshold while maintaining a relaxed antagonist [39]. In Trial 2, we did not use any FES as Trial 1 indicated that FES induced exaggerated, instantaneous antagonist-side reactions, which our protocol was, in fact, trying to minimize.

Pre-, mid-, and post-outcomes were measured using standard clinical scales [Fugl Meyer Upper Extremity Motor assessment (FMA) and Action Research Arm Test (ARAT)] to assess both gross and fine movements [40]. They were also randomized for assessment between two other therapists who were blinded to the study protocol. All subjects provided a signed written consent. Ethics approval was obtained from the Institutional Review Board of National Healthcare Group, Singapore. The set-up for the two experiments is shown in **Figure 6**.
