A Cable-Driven Exosuit for Upper Limb Flexion Based on Fibres Compliance

Abstract

Flexible soft exoskeletons, so-called exosuits, are robotic devices that interact with their users to assist or enhance muscle performance. Their lightweight design and lack of rigid parts allow assisting the user's natural motion without any constraints. They are thereby valuable in carrying out daily labour tasks and performing active stances of rehabilitation. Nonetheless, the usage of these devices in long-term applications demands anatomically adaptive designs and mechanisms to tackle textile artefacts and discrepancies in the human constitution. The soft exoskeleton described in this article is a textile-wearable design that assists shoulder and elbow flexion. The cable-driven actuation is embedded in a jacket by using several textiles and deformable parts. The inconveniences of using textile such as slipping, dampening, and pressure sores are tackled by combining textile layers with force-compliant sewing. The design also includes pieces for cable guidance, anchoring and support. These parts employ different tailoring methods so as to ease fabrication, wearing and cleaning. The motors and electronics, whose design is compatible with textiles too, are placed in a backpack. This configuration reduces forces from loads in motion and weight on the arm. Finally, the last part of the document discusses the preliminary results that have been obtained from four subjects who have worn the device.

Artificial Intelligence-Based Wearable Robotic Exoskeletons for Upper Limb Rehabilitation: A Review

“…Within the reviewed literature, the wearable exoskeletons were particularly noteworthy, representing 53% of the documents included (see Figure 5 a). In this segment, among the exoskeletons with the highest degree of portability, there were some cable operated devices [ 50 , 51 ] wherein most of the structure is flexible and lightweight. The paper of Samper-Escudero [ 50 ], pointed out that the developed exoskeleton is anatomically adaptable based on the height of each patient.…”

“…In this segment, among the exoskeletons with the highest degree of portability, there were some cable operated devices [ 50 , 51 ] wherein most of the structure is flexible and lightweight. The paper of Samper-Escudero [ 50 ], pointed out that the developed exoskeleton is anatomically adaptable based on the height of each patient. On the other hand, Varghese’s [ 51 ] development highlighted the lightness of the device, weighing approximately 950 g.…”

“…Other developments were reflected in the 12% of the reviewed literature corresponding to soft exoskeletons, which lack a rigid structure. Soft–type exoskeletons [ 50 , 51 ] promote a new generation of attrition-resistant robots that use anatomical body structures. A flexible and soft device was highlighted in [ 50 ] to assist the user’s natural movement without any restrictions.…”

“…Finally, a small percentage of studies reported the use of different types of soft or semi-rigid materials [ 32 , 50 , 51 ], corresponding to 13% of the reviewed literature; thermoformed plastic currently represents only a small portion (7%). In particular, in the orthosis shown in [ 28 ], materials such as thermoplastic urethane (TPU) were used, providing durability and flexibility to the design.…”

“…Complex systems have implemented an active operation mode [ 27 , 32 , 41 , 48 , 50 ], which was focused on providing full assistance to the affected limb. The support to the upper limbs is triggered by the measurement of the activity in the electroencephalography (EEG) or electromyography (EMG) systems, and in some cases by eye-tracking data.…”