What is rehabilitation robotics?

Rehabilitation robotics is a part of the comprehensive medical rehabilitation of patients with lost (fully or partially) or reduced functions of the upper and lower limbs because of diseases or injuries. Rehabilitation robotics is used for patients with

• ischemic stroke;
• traumatic brain injury;
• spinal injuries;
• cerebral palsy;
• Parkinson’s disease;
• multiple sclerosis and other cases of severe movement disorders.

Why is rehabilitation robotics beneficial and how can it help?

It is known that a lot of time and physical effort are required from therapists to carry out treatment connected with neurorehabilitation. A couple of specialists are usually required in the beginning of ambulation, which restricts the number of patients that a physiotherapist can treat. By comparison, robotics provides doctors with the possibility to save time, physical effort, and provide assistance to more patients.

There are many ways in which robotics can be helpful. They are:

• keeping track of movement speed, direction, amplitude, joint coordination patterns;
• providing weight support with minimal efforts and higher quality due to a longer training duration;
• giving possibility for taking more reliable and standardized tests measures;
• due to the presence of biofeedback it allows to increase the accuracy of the performed cyclic movements, assess the effectiveness of the recovery process, create a virtual play environment and work even with patients who are unable to independently perform limb movements.

Robotic recovery techniques are used at all stages of rehabilitation, starting with the ICU (intensive care unit).

Functionality

Modern devices allow training even when the patient is on bed rest. Rehabilitation robotics is carried out in active, passive, active-passive modes with preliminary diagnostics and assessment of the condition of muscles and joints. At the first stage of rehabilitation in the ICU with the help of robotic systems, early patient’s verticalization, postural correction and training of the lower limbs in a passive mode are carried out to prevent the risk of complications (cardiovascular, respiratory).

At the first and second stages of rehabilitation treatment, training is carried out to restore walking skills, active-passive development of limbs, development of joints, restoration of functions of the upper limbs (mobility of the arm, hand, restoration of fine motor skills).

**Types of devices
**
In the rehabilitation process, depending on the severity of the condition and the physiological characteristics of the patient, two groups of devices can be conditionally distinguished: lower and upper limbs recovery training devices.

Lower limb robotic rehabilitation

Obviously, gait is the main field for implication of lower limb robotic rehabilitation. Frequently the patient needs multiple therapists to help him move each joint in an appropriate way to receive great benefit. This approach towards rehabilitation is not only rather cost-intensive, but also labour consuming. But due to the use of robotics, there is no necessity for such careful attention on the doctor's part to provide practically the same mechanical therapy. When the patient starts using the robotic device, the therapist’s task is only to supervise the whole process. This is beneficial in teaching the patient correct technique with walking right initially and avoiding improper gait patterns.

Another important way robotics is included into the process of rehabilitation is its possibilities of assessment. For decades various devices have been used for one aim – collecting data and making precise measurements, which are much more reliable than those made by a human. But today there are improved robotics, which are effective in not only gathering information, but also assessing the ongoing progress on the basis of such measures as velocities, joint angles or amplitudes.

Robotics can be also applicable in improving and determining a patient’s proprioception of his lower limbs and improving volume of movements through the decreasing of joint impedance.

However, these are only some of the possible appliences of robotic therapy for rehabilitation of lower limbs. Now the robotics industry is developing and there are many opportunities to better patient monitoring.

Challenges

Together with a wide range of benefits the use of rehabilitation robotics has some drawbacks:

• pretty high costs of buying and using robotics;
• lack of clinical background for patients’ recuperation;
• the devices’ large size.

**Instances of rehabilitation robotics
**
Many lower limb robotic devices are suggested by producers, and there are some types of them:

• overground exoskeletons;

In appliance of these devices patients are commonly required possessing some upper limb strength, since crutches are frequently used side by side with the devices. They give patients an opportunity to move at the location, in a clinic or even where they live.

• body weight supported treadmill trainer (BWSTT) exoskeleton devices;

BWSTT Exoskeletons include a restraint system that supports a particular percentage of a patient’s bodyweight, when orthoses take control of knee, hip, and/or ankle movement patterns during walking.

To this type table-verticalizers with functional electrical stimulation and the Lokomat complex can be referred. It is a robotic orthoses for modeling and reproducing the act of walking, combined with a treadmill and a system for dynamic unloading of the patient's body weight. Developing the correct movement pattern and using biofeedback to involve the patient in the rehabilitation process helps to activate the sensorimotor functions of the brain that are responsible for the walking process.

• end-effector devices;

These apparatuses also provide bodyweight support by utilizing a restraint system, but alternatively to orthoses they strap the patient’s feet and ankles onto foot-plates that imitate the path of motion.

Upper limb robotic rehabilitation

Different companies all over the world have developed various devices to restore fine motor skills and hand functions. One example is electromyography (EMG)-based device which allows active therapy without the use of muscle force by the patient.

Robotic systems for the restoration of large movements of the upper limbs also allow training motor functions in a 3D working space. This helps to practice the household skills needed to socialize the patient. Arm weight support is often used. There are various ways of unloading weight: using robotic orthoses, the patient can train arms and hands in a space with six degrees of freedom, the suspension systems help to rehabilitate one or two arms at the same time. There are systems that provide two- and three-dimensional movements of the limb by attaching it to the handle.

**The future of rehabilitation robotics
**
According to experts, by 2050, the incidence of strokes in Europe will increase by 30% due to an aging population. Robotic devices will be able to help provide quality care for patients after a stroke by maintaining the required intensity of training and will save doctors from burnout syndrome. The COVID-19 pandemic has become a driver of growing interest in robotization of many industries, including the production of medical equipment, which makes it possible to carry out treatment and rehabilitation processes in compliance with sanitary and epidemiological requirements.