Physiology Meets Machines: Force Feedback, Rehabilitation and Brain Injury
Haptics offer information about touch, while force feedback is the ability of receptors in our organs to perceive varying levels of force, which results in action by the musculoskeletal system. Physiological force feedback, for example, is essential when walking or running. Touch sensors on the soles of the feet along with the force feedback that the muscles, tendons, and tissues perceive dictate the pattern in which the musculoskeletal system will move. Thus, it is clear that in haptic mechanics, both physiologically and mechanically, force feedback is assumed to be an important part of the control system and compliance.
When we look at the current use of external haptic devices that use touch and force feedback, this is typically accomplished through vibration (applications are widespread in the gaming community, surgical devices, motion stimulation, etc.)1 2, the data collected from these applications provides positive evidence that the technology is engaging for the user and that there is variability and flexibility in its application in a range of environments3.
This article proposes the use of haptic mechanics and force feedback interfaces in the medical industry with particular reference to rehabilitation following injury.
Brain Injury: Rehabilitation and Force Feedback
One of the most common forms of neural injury is stroke, which is a leading cause of long-term disability. It poses a significant burden to the patient, their families and society alike4. Standard therapy through a rehabilitation program is typically offered to enhance function of the sufferer following a stroke, however, it remains that 55-75% of stroke survivors continue to experience functional limitations5.
In a stroke model, haptic sensors and force feedback mechanics have been well-studied in their role in bilateral rehabilitation, where hemiparesis is a common result of the resulting brain injury. The addition of mechanics and their aim to promote rehabilitation of the injured side is prominent in stroke rehabilitation literature6.
The use of haptics and force feedback devices are employed in the program as a specific means to target the plasticity of the brain. Neuroplasticity describes the ability of the nervous system to adapt and change to various responses within its environment. It has been described as the ability of the nervous system to be able to reorganize its structure, function, and connections, depending on either intrinsic or extrinsic stimuli.
Neuroplasticity remains an active area of research, particularly when it comes to injury and rehabilitation. A greater understanding of the topic has led to the ability to produce more established and targeted interventions which has provided a major advantage in the area of rehabilitation and brain injury7.
There is a significant body of research to support the use of force feedback mechanics for this process.
Gerber et al., 2014, suggests there are two areas of important clinical implication in the use of haptic technology, robotics and virtual reality in brain injury8:
1. The ability of these mechanics to measure fine motor movements is far greater than that of a clinician’s evaluation and thus provides an improved source of information that may be employed into therapeutic strategies to identify areas of significance for the individual patient and by doing so improve their training and subsequent rehabilitation program.
2. The use of force feedback as a programmable device that allows for tailored adjustments to be made to individual training programs that users may use to positively affect their functional performance and movement, which may have a great effect on their overall outcome.
Andaluz et al., 2016, explains the application of haptic mechanics and force feedback in rehabilitation in that11:
1. Virtual environments with feedback in forces generate less mental burden in those who have motor alterations12.
2. The degree of satisfaction is greater and the rehabilitation has a higher impact when haptic systems are used in rehabilitation settings, particularly due to the ability to isolate the area of injury, for example, upper extremities in the event of stroke, and thus provide a more useful level of evaluation of the severity of the injury and progress being made throughout the program13.
3. The need for costly, sizable robotic systems is reduced while the degree of freedom for application is increased as haptic force feedback mechanics may be made more “patient-friendly”14.
A Boy Wearing a VR Headset While a Therapist Examines His Arm
The last point above is reiterated by Lv et al., 2016. This time, the research suggests that costly devices take a long time to develop. When there are design defects, the cost and time to completion significantly increases. Evaluation strategies with these costly robotics may only be accurately gathered once the strategy has been implemented for some length of time.
Additionally, the use of these applications are informed using static images and oral instructions which may make compliance for the patient more difficult.
With the development of virtual reality devices using haptics and force feedback mechanics, these issues may be overcome. Virtual reality environments are not only quicker to develop, they provide a faster degree of evaluation and the application and training purposes are more effective15.
Forcefeedback and VR Used in a Rehabilitation Exercise
Traumatic Brain Injury (TBI) and Force Feedback Mechanics
Larson et al., 2011, proposed that a combination of virtual reality and robotics incorporated into therapeutic exercises is well-tolerated in patients with severe TBI and shows higher engagement levels which offer benefits for attention remediation21.
Balance deficits in TBIs also benefit from the use of robotics in rehabilitation exercises. Balance boards utilizing force feedback mechanisms were shown by Cuthbert et al., 2014, to have modest positive influence on TBI patients receiving rehabilitation22.
Memory and skills acquisition has also been proposed to improve in TBI patients when using virtual reality and robotic environments during their rehabilitation. Yip & Man, 2009, found that their study subjects also improved in self-efficacy, for which they demonstrated skill transfer to a real environment23.
- Application of haptic feedback to robotic surgery. Bethea BT, Okamura AM, Kitagawa M, Fitton TP, Cattaneo SM, Gott VL, Baumgartner WA, Yuh DD J Laparoendosc Adv Surg Tech A. 2004 Jun; 14(3):191-5.
- Broeren J, Sunnerhagen KS, Rydmark M. A kinematic analysis of a haptic handheld stylus in a virtual environment: a study in healthy subjects. J Neuroeng Rehabil. 2007;4(1):13.
- Considerations for the future development of virtual technology as a rehabilitation tool. Kenyon RV, Leigh J, Keshner EA J Neuroeng Rehabil. 2004 Dec 23; 1(1):13.
- Rosamond, W., et al. Heart disease and stroke statistics—2008 update: a report from the American Heart Association Statistics Committee and Stroke Statistics Subcommittee. Circulation. 2008. 117(4):e25–146.
- Kwakkel, G., et al. Probability of regaining dexterity in the flaccid upper limb: impact of severity of paresis and time since onset in acute stroke. Stroke. 2003. 34:2181–2186.
- Adamovich, S., et al. Sensorimotor training in virtual reality: A review. Neurorehabilitation. 2009. 25(1):29-44.
- Turolla, A., et al. Haptic-Based Neurorehabilitation in Poststroke Patients: A Feasibility Prospective Multicentre Trial for Robotics Hand Rehabilitation. Comput Math Methods Med. 2013. 895492.
- Gerber, L., et al. The feasibility of using haptic devices to engage people with chronic traumatic brain injury in virtual 3D functional tasks. J Neuroeng Rehabil. 2014. 11:117.
- Brewer, B., et al. Visual feedback distortion in a robotic environment for hand rehabilitation. Brain Res Bull. 2008. 75(6):804-813.
- Ballester, B., et al. Counteracting learned non-use in chronic stroke patients with reinforcement-induced movement therapy. J Neuroeng Rehabil. 2016. 13:74.
- Andaluz, V., et al. Rehabilitation of Upper Limb with Force Feedback. IEEE ICA/ACCA. 2016. 22:99-104.
- Ramírez-Fernández, C., et al. Haptic feedback in motor hand virtual therapy increases precision and generates less mental workload. IEEE Int. Conf. on Pervasive Computing Technologies for Healthcare (PervasiveHealth). 2015. 280-286.
- Khor, K., et al. Development of CR2-Haptic: A compact and portable rehabilitation robot for wrist and forearm training. IEEEIECBES Int. Conf. on Biomedical Engineering and Sciences. 2014. 424-429.
- Renon, P., et al. Haptic interaction between human and virtual iCub robot using Novint Falcon with CHAI3D and MATLAB. IEEE-CCC Control Conference. 2013. 6045-6050.
- Lv, W., et al. Virtual Environments for Hand Rehabilitation with Force Feedback. Kubota N., Kiguchi K., Liu H., Obo T. (eds) Intelligent Robotics and Applications. ICIRA 2016. Lecture Notes in Computer Science, vol 9835. Springer, Cham.
- Chiang, V., et al. Rehabilitation of activities of daily living in virtual environments with intuitive user interface and force feedback. Disability and Rehabilitation: Assistive Technology. 2016. 12(7):672–680.
- Rizzo AS, Kim GJ. A SWOT analysis of the field of virtual reality rehabilitation and therapy. Presence. 2005. 14:119–146.
- Lee, B., et al. Cell phone based balance trainer. J Neuroeng Rehabil. 2012. 8(9):10.
- Afzal, M., et al. Effects of kinesthetic haptic feedback on standing stability of young healthy subjects and stroke patients. J Neuroeng Rehabil. 2015. 12:27.
- Zhang, L., et al. A virtual reality environment for evaluation of a daily living skill in brain injury rehabilitation: reliability and validity. Arch Phys Med Rehabil. 2003. 84(8):1118-24.
- Larsen, E., et al. Tolerance of a virtual reality intervention for attention remediation in persons with severe TBI. Brain Inj. 2011. 25(3):274-281.
- Cuthbert, J., et al. Virtual reality-based therapy for the treatment of balance deficits in patients receiving inpatient rehabilitation for traumatic brain injury. Brain Inj. 2014. 28(2):181-188.
- Yip, B., & Man, D. Virtual reality (VR)-based community living skills training for people with acquired brain injury: A pilot study. Brain Inj. 2009. 23(13-14):1017-1026.