“Dreams do come true” is the best description for the recent development in rehabilitation. In the past, we rely heavily on manual training & compensatory techniques to maximize our patient’s ability. However, manual training is labor intensive and unable to cope with the current high patient load. Compensatory techniques are passive ways for patients to adapt to the disability. With the advancement of technology and computer science, nowadays, we have many new technologies to decrease the workload of our therapists and provide not just compensation, but autonomy, to our patients.
by Dr Kwok Tsz Kin
Repetitive training will improve recovery.1 However, due to technical and manpower limitations, manual training has not provided high quantity of training required. Robotic training allowed us to overcome this hurdle. Furthermore, the quality of training can be guaranteed, and progress monitoring can be more objective.2 This allows us to fine tune the training precisely for our patients. On the other hand, clinical trials can be conducted easily with robotic training and data collection is much easier than before.
Upper limb robotic training was proven to be useful for stroke patients. When combined with virtual reality, upper limb robotic training helps to transfer the training results to daily tasks. Electromyography-Driven Neuromuscular Electrical Stimulation-Robotic Arm and Hand can offer training for stroke patients, at the same time, it is an exoskeletal type prosthesis that helps patients to use their hemiplegic upper limb functionally for daily tasks.
Lower limb robotic training was developed for patients with spinal cord injury. More evidence has shown to support the use of lower limb robots in stroke patients. This training can combine with virtual reality which help to enhance patients’ motivation. For patients with sensory impairment, lower limb robotic training combined with real time video recording enhances the self-monitoring and biofeedback of our patients. Different models of lower limb robotic exoskeleton were developed in the past years which has helped paraplegic or hemiplegic patients to walk again. This offers freedom and autonomy to these patients. Furthermore, it is not just functional, it enhances the social ability and morale of the patients.
The major drawback for robotic training is the cost. However, with increasing number of users, the cost of these robots is expected to decrease in the future. Another important problem for robotic training is the weight and size of the robots. This problem is especially prominent when patients are required to carry it to the public environment. Recent development of soft robots may be the solution to address this problem. Furthermore, soft robots can be applied to small joints of hand which cannot be possible for rigid robots.
Virtual Reality (VR) & Augmented Reality (AR)
Virtual reality (VR) is gaining its popularity in recent years for training patients.
Total submersion type VR requires patients to wear a head-mount display (HMD) and therapists can control the stimulation completely. This type of training is best for training sensory and cognitive deficit. However, VR “motion sickness” is a major problem for patients especially after prolonged use. Partial submersion type VR is less ideal for training control and usually require more space to operate. However, it significantly reduces VR “motion sickness” and is the most ideal for training mobility related problems.
VR training provides a safe environment for patients to practice risky tasks in real situations.3 There is growing evidence in training for stroke patients with hemineglect and it is now widely used in this field.4 Furthermore, patient with executive dysfunction can also benefit from this type of training because we can train the patient in a totally safe environment and we can control the exact amount of stimulation that is delivered to the patient.5
When VR combined with robotic training, we can now have highly repetitive training which simulates daily tasks. This can help the patient to transition from the hospital back to daily life much easier than before. In addition, some of the VR training can be operated at home and patients can continue the training after discharge. Some studies also postulated that VR training can improve patients’ motivation.6
With the same principle as VR, AR is extremely useful in occupational therapy training and cognitive training. Recently, AR mirror visual feedback therapy was proven to be useful for patients with phantom limb pain or neuropathic pain.7
The major drawback of AR is that it requires props that the computer can recognize in order to generate the computer image for the patients. Thanks to the exponential growth of computer technology, we are now entering the era of Mixed Reality (MR).
Besides clinical training, MR has a much higher potential for patients to utilize. A good example is gait training of patients with Parkinson Disease (PD). In order to prevent freezing, visual guide can be projected to the floor of the real environment though the HMD.8 This kind of training tools can even be extended to be used in daily life of Parkinson patients to overcome freezing. Of course, the innovation does not end here; this kind of training or assistive device can be combined with powered robotic or orthotic devices9 to create autonomy for disable patients.
MR combined with Artificial Intelligence and connectivity has a huge potential in the future. For example, patients with hemineglect can be alerted when danger approaching from the neglected side of the body. Guidance can be projected to the HMD and helps the patient to escape from dangerous situations. These endless potentials will improve the safety of our patients and reduce the needs for assistance of our patients.
Brain Computer Interface
This may be regarded as the ultimate solution in rehabilitation. Electrodes implanted to cerebral cortex pick up different pattern of electroencephalogram (EEG) signals when patient is thinking about a specific body action. The EEG signals interpreted by the computer then transformed into instructions for external devices such as robotic arm or even the computer keyboard. From this point, patients can control external devices to perform physical tasks which are functional, just by using their mind. Successful cases have been demonstrated in spinal cord injury patients, stroke and lock-in patients.10, 11
Providing control to the external devices only fulfilled half of the ultimate solution. In order to control the external devices smoothly, such as robotic arm, sensory feedback is another important domain. Currently, there are trials testing the transmission of sensory impulses to the brain from the robotic arm via the electrodes connected to the cortex of the patients. The results were promising and should be successful in the future.12
Of course, it is still the beginning of this technology and far from daily use, but we believe this is the future that we can reach and provides unbelievable autonomy to highly disabled patients in the future.
All these devices, whether is it a training device or a device for functional use, they all need prescription just like medication and requires scientific evidence to support their usage. However, the prescription process is much more complicated. It is usually a rehabilitation teams’ decision made with the patients and care givers. The decision usually made with the consideration of 4 major aspects:
Functional requirement: All these devices aimed to improve the functional level of the patients. The prescription must match with the functional needs of the patients. For example, if a patient requires large amount of long-distance outdoor activities, an electric wheelchair may be more suitable than exoskeleton robotic walking aids.
Cognitive level: Although all the new technologies are highly automatic, they still require the patients or care givers to operate. Considerable mental function is required for using this equipment effectively and safely. However, with advancements in artificial intelligence, the mental function integrity requirement may not be high in the future.
Acceptance: Almost all the new technologies are computer operated. In some cases, especially in elderly, anxiety towards computer operation may be a major hurdle for patients using these new technologies. Careful decision making with patients and care givers is essential during the process of prescription.
Affordability: All these new technologies come with a price tag and are usually relatively high. Especially when the devices are aimed at home use and patients must buy it. Furthermore, maintenance of these devices may be costly. Hopefully, when there are more users in the market and more competition from different manufacturers, they will become more affordable.
Rehabilitation physicians estimate the prognosis, combine the information from all the therapists in rehabilitation team, offer evidence-based options to patients and care givers and monitor the efficiency of the devices as well as the complications. But this is a team-base operation and patients’ progress need to be monitored.
Advancement of technology will bring about multiple benefits for disabled patients. This field is growing fast and beyond our imagination. Robotics combined with VR, AR and even MR created new opportunities for rehabilitation physicians and patients. Brain Computer Interface allowed us to have unlimited possibilities. However, no matter what technology we are using, the goal is to restore our patients’ functions. In hopes that, one day, all our disabled patients would have the abilities of ‘Iron Man’. [APBN]
About the Author
Dr. Kwok Tsz Kin (MBBS, MRCP, FHKAM, FHKCP)
Dr. Kwok graduated from The University of Hong Kong. He is fellow of Hong Kong College of Physician as well as fellow of Hong Kong Academy of Medicine in Rehabilitation Medicine. He also received training in The University of Medicine and Dentistry of New Jersey about management in neuromuscular diseases. He was one of the pioneers in using video games in daily training of his patients in Hong Kong. He has been invited to various conferences, media interviews and expert meetings to share his experience in application of technology in rehabilitation. He currently is the Consultant in Rehabilitation Medicine at Tung Wah Hospital Hong Kong and Honorary Clinical Associate Professor in Department of Medicine of The University of Hong Kong. He is also the current president of Hong Kong Association of Rehabilitation Medicine. He is the in-charge of the only Motor Neuron Diseases unit in Hong Kong at Tung Wah Hospital. He is also currently the active member of working groups in Hospital Authority Hong Kong about electronic rehabilitation platform and mobile app.