What is Haptic Feedback in Rehabilitation Technology?
You may have heard about haptic technology, or seen it mentioned in reference to rehabilitation technologies. But what is it, exactly?
For the answer you need look no further than your wrist. You can find simple haptic technology implementations in the notification features of most smart phones and watches. You may have experienced haptic technology when you receive vibration feedback from your smart watch to remind you of an upcoming deadline, or when your mapping app notifies you that you’re near your destination.
Techopedia defines haptics as “technology that uses touch to control and interact with computers.”
Haptic technology is rapidly developing in virtual gaming and robotics. In the latter, haptic devices track the user’s physical movement and how they manipulate the haptic device in order to provide realistic tactile sensations that in-turn trigger an orchestrated robotic movement (Tech Briefs, 2010).
Haptic technologies range from simple touch screen technology that registers touch input to manipulate the digital world, to advanced force-feedback haptics that combine both kinesthetic movements and tactile feedback (Chen, 2011). For instance, by moving a robot end-point you can move a digital object and feel sensations from within a virtual gaming environment. This could include stroking, pushing, pulling, or picking up an object.
Sensory Re-education with Haptics Should Play a Role in Stroke Intervention
The majority of people who sustain a stroke experience some kind of sensory loss. As many as 85% of stroke patients experience sensory impairment (Carlsson et al., 2018; Kessner et al., 2016). Impairments in light touch, deep touch, vibration feedback, stereognosis, proprioception (perception of where the body is in space) and vision are common. A recent qualitative study, which interviewed a small group of people who had experienced a stroke with mild-to-moderate upper extremity impairment, found that sensory impairment in the upper limbs affected motor control and had a negative affect on functional performance (Carlsson et al., 2018). There is clinical evidence that somatosensory dysfunction negatively influences motor function (Reding & Potes,1988; Bolognini et al.,2016).
Classic sensory re-education interventions in the clinic may include tactile discrimination and stereognosis activities with graded objects, textural differentiation, vibration therapy and hot and cold therapy. Other somatosensory interventions include functional electrical stimulation (FES) and peripheral nerve stimulation.
Virtual reality and robot-assisted therapy are multi-sensory interventions, while auditory and visual interventions include mirror therapy, observation, and music therapy interventions (Bolognini et al., 2016). Although there is evidence that sensory re-education is critical (Teasell, 2015) in neurorehabilitation, a standard of practice for this kind of rehabilitation has yet to emerge.
How Can Haptic Technologies Change Rehabilitation?
While hospitals and outpatient clinics are constantly moving with peer-to-peer and therapist interactions, the environment cannot always be visually stimulating or engaging from a sensory perspective. But haptic technologies, such as robotic therapy and virtual reality, can provide engaging sensory environments.
For instance, a rehabilitation robot such as the BURT can provide active visual, auditory, proprioceptive, and vibration feedback from within a task. Different haptic technologies can provide varying levels of sensory feedback that can be graded by intensity. Haptics can be used to translate a sensation (such as a tactile sensation of an object or graded vibration feedback) through an end-effector or to provide therapeutic guidance to the patient during an activity.
In addition to tactile and somatosensory applications, haptic technology can provide graded resistance against the patient’s movement. For example, haptic technology might add weight to a digital object, such as a virtual bottle on a video screen, or increase resistance to an exercise within a therapeutic gaming platform.
These technologies which are rapidly developing, have tremendous potential for the application of sensorimotor practice by creating new therapeutic tasks within a traditional rehabilitation environment.
Have questions about the application of haptics in rehabilitation? Post your comments below, or contact me at email@example.com
Article written by Holly Mitchell, MOT, OTR/L
To learn more about the role of haptics in stroke rehab, see the references below.
Techbriefs Media Group, C. G. (2010, August 1). Controlling Robotics Precisely With Haptic Technology. Retrieved from https://www.techbriefs.com/component/content/article/tb/features/articles/9278
Chen, D. (2011, January 01). Touch Me, Heal Me: Haptic Solutions for Rehabilitation. Retrieved from https://www.medicaldesignbriefs.com/component/content/article/mdb/features/articles/8938
Carlsson, H., Gard, G., & Brogårdh, C. (2018). Upper-limb sensory impairments after stroke: Self-reported experiences of daily life and rehabilitation. Journal of Rehabilitation Medicine,50(1), 45-51. doi:10.2340/16501977-2282
Kessner SS, Bingel U, Thomalla G. Somatosensory deficits after stroke: a scoping review. Top Stroke Rehabil 2016; 23: 136–146.
Bolognini, N., Russo, C., & Edwards, D. J. (2016). The sensory side of post-stroke motor rehabilitation. Restorative Neurology and Neuroscience,34(4), 571-586. doi:10.3233/rnn-150606
Reding MJ, Potes E. Rehabilitation outcome following initial unilateral hemispheric stroke. Life table analysis approach. Stroke. 1988;19(11):1354–1358.
Teasell, R. (2015). Evidence-Based Review of Stroke Rehabilitation 17th edition. Retrieved from http://www.ebrsr.com/sites/default/files/documents/executive-summary-srebr_final_16ed.pdf