# The Impact of COVID on Lower-Limb Exoskeleton Robotic System Patents--A Review
## 4 Discussion
### General Discussion on the Results of the Analysis of the Patent Platforms
In that case, the following pation is designed to adjust pelvic movement with the same objective: gait training to help people have a more natural walk movement. The first patent focuses on knee joint reinforcement, followed by concepts designed to adjust pelvic movement with the same objective: gait training to help people have a more natural walk movement. The Active Knee Rehabilitation Orthotic System (ANdROS) [27] is intended to assist everyday tasks rather than gait retraining. The invention describes wearable and portable assistive equipment for gait neuro-rehabilitation that addresses primary gait abnormalities by reinforcing around the knee joint a preferred gait pattern via correcting torque fields applied. The patent is a wearable assistive device for gait rehabilitation in patients who have lost motor control due to a neurological condition, such as a stroke. A motorized footplate with force feedback and an exoskeleton to regulate pelvic movement during gait training [28] makes this innovation perfect for implementing ecologically sound procedures that accurately simulate real-life settings and maximize motor improvements in stroke patients. In addition, to optimize rehabilitation effects, an active pelvic prosthesis with a non-treadmill pedal system is necessary. The following published patents were born from ideas intended to improve mobility further. Therefore, exosuit-based systems with actuators were developed to provide active support for the ankle. Fixed in three points on the leg and created from a lightweight material, it shows comfort for the user and improves torque. This patent [29] discusses three-point contact with the leg and a series of elastic elements for improved torque control. Apart from their small size (0.88 kg), these devices can monitor joint angle and torque. A combination of proportional feedback and suspension injection is employed during walking trials to modulate torque. The closed-loop torque control of the exoskeleton devices was evaluated by controlling 50 N-m and 20 N-m linear chirps in intended torque while using exoskeletons and measuring bandwidths more significant than 16 Hz and 21 Hz, respectively. There was a maximum torque of 120 N-m and a tracking error of 2.0 N-m. These testbeds demonstrate how exoskeletons may be employed to study a variety of control and support paradigms rapidly. The document provides an exoskeleton system that comprises a cable, a lever attached to the cable, a frame having a strut directing the cable to the lever, and a motor coupled to the cable and adapted to cause the cable to deliver torque around the rotating joint. In addition to previous innovations, it was considered the proper time to introduce smart materials that will block or even actuate joints to expand the possibilities of implementation for wearable robotic devices. However, smart material-based exoskeleton publications are found in a minimal number and provide a substantial implementation complexity; therefore, such a type of patent is to be considered. The work [30] aims to offer an exoskeletal device with semi-active joints that can lower articular tensions caused by limb weight, reduce physical labor load, and promote physical workouts for motor ability rehabilitation following cerebral or orthopedic accidents. In addition, other objectives are realized via a mechanism, namely, an exoskeleton with at minimum two links joined by an electro- or magneto-rheological fluid joint. Further improvements of the exoskeletons are being developed concerning the user's biological skeleton and flexible materials to deliver improved customized mobility according to the user's needs. With a soft exosuit system and an actuator system, the concept [31] provides active support for natural actions, such as normal leg movement. The soft exosuit uses flexible materials and actuators and depends on the user's biological skeleton to aid in applying forces and transferring loads, unlike previous art-rigid exoskeletons.