Management of skin-related adverse events during locomotor training with robotic-assisted body weight supported treadmill: A case report

Occurrence and Type of Adverse Events During the Use of Stationary Gait Robots-A Systematic Literature Review

Robot-assisted gait training (RAGT) devices are used in rehabilitation to improve patients' walking function. While there are some reports on the adverse events (AEs) and associated risks in overground exoskeletons, the risks of stationary gait trainers cannot be accurately assessed. We therefore aimed to collect information on AEs occurring during the use of stationary gait robots and identify associated risks, as well as gaps and needs, for safe use of these devices. We searched both bibliographic and full-text literature databases for peer-reviewed articles describing the outcomes of stationary RAGT and specifically mentioning AEs. We then compiled information on the occurrence and types of AEs and on the quality of AE reporting. Based on this, we analyzed the risks of RAGT in stationary gait robots. We included 50 studies involving 985 subjects and found reports of AEs in 18 of those studies. Many of the AE reports were incomplete or did not include sufficient detail on different aspects, such as severity or patient characteristics, which hinders the precise counts of AE-related information. Over 169 device-related AEs experienced by between 79 and 124 patients were reported. Soft tissue-related AEs occurred most frequently and were mostly reported in end-effector-type devices. Musculoskeletal AEs had the second highest prevalence and occurred mainly in exoskeleton-type devices. We further identified physiological AEs including blood pressure changes that occurred in both exoskeleton-type and end-effector-type devices. Training in stationary gait robots can cause injuries or discomfort to the skin, underlying tissue, and musculoskeletal system, as well as unwanted blood pressure changes. The underlying risks for the most prevalent injury types include excessive pressure and shear at the interface between robot and human (cuffs/harness), as well as increased moments and forces applied to the musculoskeletal system likely caused by misalignments (between joint axes of robot and human). There is a need for more structured and complete recording and dissemination of AEs related to robotic gait training to increase knowledge on risks. With this information, appropriate mitigation strategies can and should be developed and implemented in RAGT devices to increase their safety.

Prototype Measuring Device for Assessing Interaction Forces between Human Limbs and Rehabilitation Robots - A Proof of Concept Study

Rehabilitation robots can provide high intensity and dosage training or assist patients in activities of daily living and decrease physical strain on clinicians. However, the physical human robot interaction poses a major safety issue, as the close physical contact between user and robot can lead to injuries. Moreover, the magnitude of forces as well as best practices for measuring them, are widely unknown. Therefore, a measurement setup was developed to assess normal and tangential forces that occur in the contact area between an arm and a splint. Force sensitive resistors and a force / torque sensor were combined with two different splint shapes. Initial experiments indicated that the setup gives some insight into magnitudes and distribution of normal forces on the splint-forearm-interface. Experiment results show a dependency of force distributions on the splint shape and sensor locations. Based on these outcomes, we proposed an improved setup for subsequent investigations.