Effectiveness of Robotic Rehabilitation in Stroke Patients

Posted on May 10, 2022

Only 5 to 20% of patients exhibit complete functional recovery after a stroke event, while 80% reveal a variable degree of impairment and inability to attend to daily life activities. Pain, joint constraint spasticity, and skin or vascular damage are classic concerns observed in stroke survivors with upper limb disability and signify a major rehabilitation challenge in the subacute or chronic phase. 

In relation to the growing prevalence of stroke cases in an aging society, there is a demanding need for groundbreaking rehabilitation approaches. One of the most promising strategies intended to recover upper limb function after stroke is robotic rehabilitation (RR).

The scientific community recognizes the efficacy of robotic devices for the treatment and rehabilitation of post-stroke upper limb disorders. Understanding the regulatory principles of neurophysiological clinical and biomechanical adaptations of each available means of RR is the key to attaining the best outcomes when treating various and specific upper limb disorders affecting stroke patients. 

To contribute to the post-stroke functional rescue of the hand, named Gloreha, a newly designed RR device has recently been presented in convalescence. This new device comprises a soft exoskeleton comparable to a glove that encases the fingers and wrist of the paralyzed hand with Velcro straps and attachments.

Passive mobilization of the fingers is provided by a hydraulic system that generates force transmitted through semi-rigid cables. The main novelty of this new RR device is that it enables well-calibrated sequential movement of every finger while the patient notices the action induced by the device in a concurrent modality. Different ranges of motion and exercises can be selected through the dedicated software.

SINFONIA robotic glove can work in diverse ways:

  • BIMANUAL MIRROR TRAINING: The movements of the ‘healthy’ hand is recognized by the device and reproduced on the affected limb on the opposite side through the robotic glove. Thanks to Sinfonia, even the paralyzed patients on one side of the body can actively guide the exercise. 
  • PASSIVE: Mobilization is supported by multi-sensory stimulus (3D animation, interaction with objects, voice guidance sound effects, musical accompaniment) to ensure patient involvement and extend the cortical areas reached by neuroplasticity mechanisms. The robotic glove generates finger extension and flexion according to customizable considerations.
  • ACTIVE-ASSISTED: Proposed exercises involve the patient initiating a motor task by themself; the robotic glove tracks the patient’s activity, and the motorized system interposes to help only when necessary. Performance indicators give instant feedback on the patient’s independent inflection and extension degree.
  • ACTIVE: Serious games stimulate the patient to do his best to exploit his distal active ROM. Exercises train hand opening,  fist closing,  single finger flexion-extension, and tridigital pinch. Instinctual graphs at the end of the exercise show the patient and therapist the recorded trend, session after session.

Main features:

  • To increase the degree of involvement and motivation, finger flexion and extension are dynamically activated by the patient
  • The mirror mechanism intensifies the cortical area stimulation by observing the 3D hands in movement and executing functional tasks and serious games with the real stuff.
  • Compared to traditional Mirror Therapy, Sinfonia enables one to go beyond the movement illusion: real motor training can be generated by the robotic glove on the hand with a motor deficit, increasing the rehabilitation potential. 

Effectiveness of Robotic Rehabilitation

The outcome measured the total hemoglobin profiles and tissue oxygenation index (TOI) in the muscle tissue evaluated through near-infrared spectroscopy. The Motricity Index and modified Ashworth Scale for upper limb muscles were used to assess the mobility of the upper extremity. 

Robotic assistance reduced spasticity after the intervention in the upper limb by 68.6%. The Motor function Index was unchanged in these patients after treatment. Regarding changes in muscle perfusion, significant improvements were found in total hemoglobin. There were noteworthy differences between the pre-and post-treatment modified Ashworth scale. 

The present work provides novel proof that robotic hand assistance induced changes in diminished spasticity, local muscle blood flow, and oxygen supply and decreased subject-reported symptoms of heaviness and stiffness in subjects with post-stroke hemiparesis.