Optimizing Design and Control Methods for Using Collaborative Robots in Upper Limb Rehabilitation

In this article, we address the development of a robotic rehabilitation system for the upper limbs based on collaborative end-effector solutions. The use of commercial collaborative robots offers significant advantages for this task, as they are optimized from an engineering perspective and ensure safe physical interaction with humans. However, they also come with noticeable drawbacks, such as the limited range of sizes available on the market and the standard control modes, which are primarily oriented toward industrial or service applications. To address these limitations, we propose an optimization-based design method to fully exploit the capability of the cobot in performing rehabilitation tasks. In addition, we introduce a novel control architecture based on an admittance-type virtual fixture method, which constrains the motion of the robot along a prescribed path. This approach allows for an intuitive definition of the task to be performed via programming by demonstration and enables the system to operate both passively and actively. In passive mode, the system supports the patient during task execution with additional force, while in active mode, it opposes the motion with a braking force. Experimental results demonstrate the effectiveness of the proposed method

Path-Constrained Admittance Control of Human-Robot Interaction for Upper Limb Rehabilitation

In this paper, the problem of robotic rehabilitation of upper limbs is addressed by focusing attention on the control of a standard collaborative robot for those training activities that can be performed with the aid of an end-effector type system. In particular, a novel admittance control, that constrains the motion of the robot along a prescribed path without imposing a specific time law along it, has been devised. The proposed approach exploits the features of the arc-length parameterization of a generic curve to obtain a simple control formulation able to guide the patient in both a passive or an active way, with the possibility of supporting the execution of the task with an additional force or opposing the motion with a braking force. Being the method independent from the particular curve considered for the constraint specification, it allows an intuitive definition of the task to be performed via Programming by Demonstration. Experimental results show the effectiveness of the proposed approach

Polypharmacy and malnutrition in older people: A narrative review

Polypharmacy is the simultaneous use of multiple medicines, usually more than five. Polypharmacy is highly prevalent among older individuals and is associated with several adverse health outcomes, including frailty. The role of polypharmacy in nutritional status seems to be crucial: although a clear association between polypharmacy and malnutrition has been widely reported in older people, the magnitude of the effect of increased number of drugs in combination with their type on the risk for malnutrition remains to be largely explored. Therefore, this review aims to discuss the association between polypharmacy and malnutrition in older people and to provide suggestions for its management. Polypharmacy is prevalent among malnourished frail patients, and the relative contribution of comorbidities and polypharmacy to malnutrition is difficult to be determined. Several mechanisms by which commonly used medications have the potential to affect nutritional status have been identified and described. Deprescribing (i.e., a systematic process of identification and discontinuation of drugs or a reduction of drug regimens) could be an essential step for minimizing the effects of polypharmacy on malnutrition. In this regard, the literature suggests that in older patients taking several medications, the best method to solve this problem is the comprehensive geriatric assessment, based on a holistic approach, including drug review, to find potential unnecessary and inappropriate medications. Nutritional and deprescribing interventions must be tailored to patient needs and to the local context to overcome barriers when applied in different settings