[ARTICLE] Development and evaluation of a novel music-based therapeutic device for upper extremity movement training: A pre-clinical, single-arm trial – Full Text

Abstract

Restoration of upper limb motor function and patient functional independence are crucial treatment targets in neurological rehabilitation. Growing evidence indicates that music-based intervention is a promising therapeutic approach for the restoration of upper extremity functional abilities in neurologic conditions such as cerebral palsy, stroke, and Parkinson’s Disease. In this context, music technology may be particularly useful to increase the availability and accessibility of music-based therapy and assist therapists in the implementation and assessment of targeted therapeutic goals. In the present study, we conducted a pre-clinical, single-arm trial to evaluate a novel music-based therapeutic device (SONATA) for upper limb extremity movement training. The device consists of a graphical user interface generated by a single-board computer displayed on a 32” touchscreen with built-in speakers controlled wirelessly by a computer tablet. The system includes two operational modes that allow users to play musical melodies on a virtual keyboard or draw figures/shapes whereby every action input results in controllable sensory feedback. Four motor tasks involving hand/finger movement were performed with 21 healthy individuals (13 males, aged 26.4 ± 3.5 years) to evaluate the device’s operational modes and main features. The results of the functional tests suggest that the device is a reliable system to present pre-defined sequences of audiovisual stimuli and shapes and to record response and movement data. This preliminary study also suggests that the device is feasible and adequate for use with healthy individuals. These findings open new avenues for future clinical research to further investigate the feasibility and usability of the SONATA as a tool for upper extremity motor function training in neurological rehabilitation. Directions for future clinical research are discussed.

Introduction

Effective use of the arm and hand to reach, grasp, release, and manipulate objects is often compromised in individuals with neurologic disorders such as cerebral palsy [1], stroke [2, 3], Parkinson’s Disease [4, 5], among others. Impairments of upper extremity function include reduced muscle power, sensory loss, increased muscle spasticity, and lack of motor control [1, 6–8], resulting in significant long-term functional deficits with relevant impact on patients’ activities of daily living, independence, and quality of life [9–12]. Therefore, improving upper limb functional abilities and promoting functional independence are crucial treatment targets for neurological rehabilitation.

Functional restoration of the upper extremity is thought to be achieved through a combination of neurophysiological and learning-dependent processes that involve targeted training to restore, substitute, and compensate the weakened functions [13, 14]. Frequently reported neurorehabilitation approaches for upper limb movement in cerebral palsy [15, 16], stroke [13, 17], and Parkinson’s Disease [18, 19] include standard treatment methods such as general physiotherapy (i.e., muscle strengthening and stretching), constraint-induced movement therapy and bimanual training, as well as technology-based approaches (i.e., virtual reality, games, and robot-assisted training) [20–26] and music-based interventions [27–29].

There is growing evidence that music-based interventions are a promising therapeutic approach for the restoration of upper extremity functional abilities in neurologic conditions including stroke [30, 31], cerebral palsy [32], and Parkinson’s Disease [28, 33]. For instance, there is extensive research on the effectiveness of therapeutic techniques such as Music-supported Therapy and Therapeutic Instrumental Music Performance in rehabilitating arm paresis after stroke through musical instrument playing [30, 34–40]. Similarly, active musical instrument playing (i.e., piano) also seems to improve manual dexterity and finger and hand motor function in individuals with cerebral palsy [32, 41–43]. Furthermore, consistent evidence indicates that interventions using rhythmic auditory cues or rhythmically-enhanced music are effective to increase muscle activation symmetry [44], improve range of motion and isometric strength [45], enhance spatiotemporal motor control [46], and decrease compensatory reaching movements [44].

Music-based movement rehabilitation for upper limb training is particularly interesting because playing a musical instrument provides real-time multisensory information that enhances online motor error-correction mechanisms and supplements possible perceptual deficits [47–49]. Research has also shown that the engagement of multisensory and motor networks during active music playing promotes neuroplastic changes in functional networks and structural components of the brain, which are crucial neurophysiological processes for neurologic recovery [50–53]. In addition, there is robust evidence that the use of metronome or beat-enhanced music is important to support movement training as the continuous-time reference provided by the rhythmic cues allow for movement anticipation and motor preparation, bypassing the movement timing dysfunction through the activation of alternate or spared neural pathways [33, 54]. Finally, emotional-motivational aspects of music-making also play a significant role in the rehabilitating effects of music-based intervention through music-induced changes in mood, arousal, and motivation [27, 55], with potential effects on perceived physical endurance and fatigue [30, 56].

Traditionally, music-based interventions for the rehabilitation of upper extremity generally involve the use of acoustic musical instruments such as guitar, piano, and pitched and non-pitched percussive instruments [38, 42]. However, traditional instruments can impose limitations for those with significant cognitive or physical impairments as they require more resistance to press a key or to move a string and are less adaptable to the patient’s needs. Recently, studies have acknowledged the relevance of music technology to increase the availability and accessibility of music-based therapy for patients with neurological disorders in different settings, including hospitals, communities, and home environment [57–60]. For example, the use of programmable devices can help patients to exercise independently in addition to scheduled caregiver-guided sessions, thus increasing treatment intensity [58]. Digital music and sound devices can provide enhanced auditory feedback to kinematic movement components such as velocity and acceleration, range of motion, joint angles, spatial and temporal limb trajectories, even in stages of limited physical movement capability [57]. Additionally, technology may assist therapists in the implementation of individual therapeutic goals and provide immediate assessment of measurable changes with objective outcome measures (e.g., total movement time, movement variability, force, inter-response interval).

The introduction of music technology with the use of digital musical instruments, such as keyboards and drum pads [30, 38] and, more recently, touchscreen devices (e.g. tablets) using commercially available music software [40, 61, 62], have provided novel approaches for the application of active musical instrument playing in the rehabilitation of upper extremity motor function. For instance, electronic keyboards and digital sound surfaces enable users with complex needs the possibility to play a musical instrument in an adapted form to train fine and gross movements of the paretic extremity [30, 38]. However, the therapeutic sessions are commonly provided by a therapist at a rehabilitation center or hospital, thus limiting its availability for additional and independent at-home-practice. The use of mobile tablets in music therapy has notable advantages in this regard, as they provide affordable, accessible, and portable alternatives to digital music instruments. However, there is a lack of hardware and software developed specifically for clinical practice, and the use of touchscreen devices in music therapy is often limited by resources developed for the wider consumer market [63]. Therefore, there is a clear need for the development of new technology to address this important gap in music-based neurologic rehabilitation. In light of this need, a novel music-based therapeutic device for upper extremity movement training was developed with the ultimate goal to improve upper extremity motor function, to increase independent patient engagement, to enhance treatment quality, intensity, and compliance, and to assist therapists during treatment implementation and assessment.

The objective of this study is to describe a novel music-based therapeutic device called SONATA and to conduct a pre-clinical, single-arm trial to test the device with healthy individuals. For this purpose, four motor tasks requiring finger and hand movements were implemented in a convenience sample of healthy participants to examine the system’s operational modes, which allow users to play musical melodies on a touchscreen keyboard (Tasks 1–3) or draw figures/shapes (Task 4), and to assess the reliability of the device’s main features such as the presentation of sequences of audiovisual stimuli at a pre-defined order and record response and movement data (e.g., reaction time, correct/incorrect responses, inter-response interval). Specifically, Tasks 1 to 3 are adaptations of motor sequence learning tasks that have been previously used in research and/or clinical practice [34, 38, 64, 65] and involve the presentation of melodies that vary in length, tempo, and complexity that are reproduced by the participant by pressing different keys represented by squares displayed on the device’s touchscreen. Such tasks are often implemented in active music playing therapy to train finger dexterity, range of mobility, functional hand movements, spatial-temporal control, and limb coordination [34, 37, 39, 45, 51]. In addition, training of finger movements involving tracking a target or tracing a line on a computer screen is commonly implemented in motor rehabilitation to improve spatial-temporal control and fine motor skills of the paretic hand [66–68]. However, finger tracking training is not usually implemented in music-based interventions due to limitations imposed by the structure of the majority of acoustic musical instruments. Therefore, Task 4 is an example of an exercise for spatial accuracy training of continuous motions via sonification, whereby the position and movement of the finger are captured in real-time and transformed into different sounds.

Materials and methods

The experimental procedures conformed with the Declaration of Helsinki and were approved by the Local Ethics Committee of the Faculty of Psychology and Movement Science of the Universität Hamburg. All participants were fully informed about the nature of the study and provided written informed consent to participate. The individual in this manuscript has given written informed consent (as outlined in PLOS consent form) to publish these case details (Fig 4).

Device hardware and software

The Sonification Arm Training Apparatus (SONATA) consists of a custom-made graphical user interface generated by a single-board plugged-in computer (Raspberry Pi 2 B with HiFiBerry) displayed on a 32” touchscreen (iiyama ProLite T3234MSC-B3X; visible screen size: 698.4 x 392.8 mm; resolution: 1920 x 1080 pixels, pixel spacing: 0.364 x 0.364 mm) with built-in speakers and controlled wirelessly via Wi-Fi by a battery-powered computer tablet (Acer One 10) (Fig 1). The hardware and software of the system have been designed to minimize any latency (≤ 30 ms) between user input and sound output.

Fig 1. Device’s touchscreen, graphic user interface, and controller tablet.

https://doi.org/10.1371/journal.pone.0242552.g001

[…]

Continue