Introduction:
The most common catastrophic disabilities caused by neurological illnesses are the loss of movement in an arm or leg and the resulting loss of freedom of movement. When these conditions were once thought to be incurable, therapy frequently centered on teaching patients how to use their "good side." Fortunately, research indicates that "task-specific learning" in neurorehabilitation, based on neuroplasticity, suggests that everyday living skills can be honed and enhanced in neurological patients by constant repetition. This need is met by robotic treatment, which also allows for rigorous functional locomotion therapy with improved feedback.
Robotics can compensate for patients' lack of strength or motor control at speeds matched explicitly to their remaining motor functions. At the same time, ongoing input gives them a subjective sense of progress. These features make robotics a possible aid in rehabilitation for trainers and patients whose roles remain crucial to the procedure. Robotic neurorehabilitation is appealing due to its ease of deployment potential, adaptability to various motor impairments, and excellent measurement reliability.
What Are the Goals of Robotics in Neurorehabilitation?
Upper limb function development and gait re-education support are the two main objectives of therapy using rehabilitation robots.
Robots for rehabilitation are typically utilized when the central nervous system has been damaged, most often after a stroke. Regarding these robots, numerous clinical studies and meta-analyses have been carried out. Researchers examined 45 randomized controlled studies involving 1619 participants to determine the effectiveness of electromechanical arm training. They discovered that this type of treatment encourages development in arm function, muscle strength, and the performance of daily living activities. Although 24 distinct devices were employed, the study techniques were very different.
One popular technique for gait re-education is robot-mediated training on a treadmill. In a Cochrane analysis that included 36 studies and 1472 participants, researchers discovered that post-stroke patients who obtained such training in addition to conventional physiotherapy were significantly more likely to attain independent walking than those who had conventional therapy alone.
What Are the Key Principles That Robotic Devices Should Adhere To?
Instead of listing the advantages and disadvantages of all currently marketed rehabilitative robotic technologies, a broad framework describes some essential guidelines these devices should adhere to.
First, robotic systems should support a variety of tasks that enable the user to practice them frequently if advances in a patient's capacity to complete a task are the consequence of motor learning and training a new internal model. The capacity to practice something repeatedly is crucial to "getting it right"; nevertheless, to promote learning, the person must make mistakes and receive reliable feedback on those failures. As a result, performance must be accurately represented.
The robot control techniques used throughout the training will significantly impact this feedback. For instance, a visible display must show the degree and direction of assistance given if the robot helps the subject's limbs move along a predetermined kinematic trajectory. The patient may need clarification on this and find it quite confusing. If the robot is operated in an impedance mode, on the other hand, the visual feedback may only be the position of the limbs.
Diversity is yet another crucial quality that robotic devices should have. When an accurate internal model is created, motor learning frequently generalizes, although this generalization is limited. A basketball is not guaranteed to become an accurate 3-point shooter even if it has the ideal motor control method for making free throws. The concept is that robotic equipment should enable them to practice a wide range of tasks instead of merely allowing people to walk or reach in a horizontal plane. These variants should contain random and planned perturbations to help patients learn how to fix errors.
Finally, about the ideas mentioned above, it is crucial that patients in rehabilitation are allowed to struggle with the tasks they are attempting. Failure allows individuals to try the task using a specific motor control method, assess if it works, and modify their approach. Additionally, it enables the creation of error correction techniques like impedance control via reflex circuit modulation. The motor learning process depends on this kind of error correction. Patients can also test the limits of task success through error experience. For instance, sufferers must comprehend how big of a step they can take without losing their balance or stability regarding gait. Robotic tools are ideal for such tasks because they may give the patient a secure setting to take risks, test their boundaries, and discover how much motor capacity their new motor control system has.
What Are the Types of Robotic Devices Used in Neurorehabilitation?
End-effector devices and exoskeletons are the two primary robotic devices for neurorehabilitation based on the many forms of physical human-robot contact.
Robotic devices, known as "end-effector-based systems," are outfitted with a particular interface that mechanically restrains the distal portion of a human limb (such as the human wrist). These systems do not have complete control over the kinematic chain, allowing the human limb to fully adjust to outside disturbances and movements made by the end-effector robot. As a result, in this device, only the distal body segment coupled to the end-effector may be controlled directly; further data regarding the forces acting on and/or the locations of the other components of the human limb are collected indirectly.
Contrarily, exoskeletons faithfully mimic the kinematics of the human limb and support its movements by manipulating the position and orientation of each joint. The devices' primary function is to couple and coordinate the mechanical joints with those of the human body. For instance, in upper limb robotics, the devices are connected to the limb at the forearm or arm level. Additionally, the number of actuated joints and the range of motion (ROM) are appropriately selected to maximize control. As a result, the patient's movements are more closely monitored when using the exoskeleton. However, doing so comes at a higher cost of the complexity of the degree of freedom control.
What Are the Future Robotics Challenges That Must Be Overcome?
There are many problems to be resolved and many questions to be resolved in rehabilitation robots. Future consideration should be given to the following issues.
Clinically:
In the medical field, standardized clinical trial techniques are required, along with evaluations that make studies comparable and acceptable for meta-analyses. Guidelines for robotic trials in research could be beneficial. To avoid confusion, high-tech robotic and non-robotic equipment should have distinct definitions and names.
The research mentioned above would offer suggestions for responding to inquiries about the methods used for patient selection and treatment. The trials should focus on which patients might benefit more from robotic rehabilitation. Clinical guidelines should be created once there is data to support them rather than just experience.
Technically:
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Make use of the entire range of movements.
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Obtain more refined sensory input from the patient.
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Utilize artificial intelligence to enable decision-making regarding the treatment plan.
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Create workouts that practice daily-life functions using actual things rather than merely virtual ones.
Other Factors:
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Expand the selection of robots that can be used at home.
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Expand the possibilities for using robots daily, including as supportive gadgets and training tools.
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Boost the cost-to-benefit ratio.
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The advancement of artificial intelligence will necessitate careful attention to moral principles.
Conclusion:
A promising prospect to increase treatment options and enhance results for people with disabilities primarily brought on by central nervous system abnormalities is the employment of robots and other interactive technology. Clinical studies indicate that using modern robotic instruments may benefit patients in specific ways. Additionally, robots' effectiveness may be increased with further technological advancement and their appropriate placement in the rehabilitation program.
