Design of arm exercises for rehabilitation assistance

This paper presents the design and testing of arm exercises for rehabilitation assistance. The description of the human arm is presented together with the arm motion impairments. The motion planning for four arm exercises and the experimental procedure for data collection are described. A procedure to generate reference trajectories by regression analysis is explained. The procedure is numerically validated to prove the successfully generation of a representative trajectory for a set of trajectory samples. References trajectories are generated using the proposed procedure for four arm exercises through trajectory samples acquired from 12 subjects. The obtained reference trajectories can be used for rehabilitation assisting the traditional therapies using an automatized device

An Autotuning Cable-Driven Device for Home Rehabilitation

© 2021 Jhon F. Rodríguez-León et al. Out of all the changes to our daily life brought by the COVID-19 pandemic, one of the most significant ones has been the limited access to health services that we used to take for granted. Thus, in order to prevent temporary injuries from having lingering or permanent effects, the need for home rehabilitation device is urgent. For this reason, this paper proposes a cable-driven device for limb rehabilitation, CUBE2, with a novel end-effector (EE) design and autotuning capabilities to enable autonomous use. The proposed design is presented as an evolution of the previous CUBE design. In this paper, the proposed device is modelled and analyzed with finite element analysis. Then, a novel vision-based control strategy is described. Furthermore, a prototype has been manufactured and validated experimentally. Preliminary test to estimate home position repeatability has been carried out

A bioinspired humanoid foot mechanism

© 2021 by the authors. Licensee MDPI, Basel, Switzerland. This paper introduces an innovative robotic foot design inspired by the functionality and the anatomy of the human foot. Most humanoid robots are characterized by flat, rigid feet with limited mobility, which cannot emulate the physical behavior of the foot-ground interaction. The proposed foot mechanism consists of three main bodies, to represent the heel, plant, and toes, connected by compliant joints for improved balancing and impact absorption. The functional requirements were extracted from medical literature, and were acquired through a motion capture system, and the proposed design was validated with a numerical simulation

Test-Retest, Inter-Rater and Intra-Rater Reliability for Spatiotemporal Gait Parameters Using SANE (an eaSy gAit aNalysis systEm) as Measuring Instrument

Studies have demonstrated the validity of Kinect-based systems to measure spatiotemporal parameters of gait. However, few studies have addressed test-retest, inter-rater and intra-rater reliability for spatiotemporal gait parameters. This study aims to assess test-retest, inter-rater and intra-rater reliability of SANE (eaSy gAit aNalysis system) as a measuring instrument for spatiotemporal gait parameters. SANE comprises a depth sensor and a software that automatically estimates spatiotemporal gait parameters using distances between ankles without the need to manually indicate where each gait cycle begins and ends. Gait analysis was conducted by 2 evaluators for 12 healthy subjects during 4 sessions. The reliability was evaluated using Intraclass Correlation Coefficients (ICC). In addition, the Standard Error of the Measurement (SEM), and Smallest Detectable Change (SDC) was calculated. SANE showed from an acceptable to an excellent test-retest, inter-rater and intra-rater reliability; test-retest reliability ranged from 0.62 to 0.81, inter-rater reliability ranged from 0.70 to 0.95 and intra-rater ranged from 0.74 to 0.92. The subject behavior had a greater effect on the reliability of SANE than the evaluator performance. The reliability values of SANE were comparable with other similar studies. SANE, as a feasible and markerless system, has large potential for assessing spatiotemporal gait parameters

A Smart Stent for Monitoring Eventual Restenosis: Computational Fluid Dynamic and Finite Element Analysis in Descending Thoracic Aorta

Even though scientific studies of smart stents are extensive, current smart stents focus on pressure sensors. This paper presents a novel implantable biocompatible smart stent for monitoring eventual restenosis. The device is comprised of a metal mesh structure, a biocompatible and adaptable envelope, and pair-operated ultrasonic sensors for restenosis monitoring through flow velocity. Aside from continuous monitoring of restenosis post-implantation, it is also important to evaluate whether the stent design itself causes complications such as restenosis or thrombosis. Therefore, computational fluid dynamic (CFD) analysis before and after stent implantation were carried out as well as finite element analysis (FEA). The proposed smart stent was put in the descending thoracic section of a virtually reconstructed aorta that comes from a computed tomography (CT) scan. Blood flow velocity showed that after stent implantation, there is not liquid retention or vortex generation. In addition, blood pressures after stent implantation were within the normal blood pressure values. The stress and the factor of safety (FOS) analysis showed that the stress values reached by the stent are very far from the yield strength limit of the materials and that the stent is stiff enough to support the applied loads exported from the CFD results

Assessing Stiffness, Joint Torque and ROM for Paretic and Non-Paretic Lower Limbs during the Subacute Phase of Stroke Using Lokomat Tools

The efficacy of Lokomat on motor recovery in stroke patients is well known. However, few studies have examined Lokomat tools to assess stiffness, joint torque and range of motion (ROM) during the subacute phase of stroke. The purpose of this retrospective observational study is to assess the changes of joint torque, ROM and stiffness that were estimated with Lokomat tools, namely L-FORCE (lower limb-force), L-ROM (lower limb-range of motion)and L-STIFF (lower limb-stiff), for paretic and non-paretic lower limbs in the subacute phase of stroke, assuming that the tools were able to measure these changes. The data come from 10 subjects in the subacute phase who had their first ever-stroke and followed a treatment that included Lokomat. The measurements came from basal assessments (T0) and one-month follow-up (T1). The measures were compared between paretic and non-paretic legs, and between T0 and T1. Significant differences in stiffness, joint torque and ROM were obtained between the paretic and non-paretic limbs at both T0 and T1. A non-significant trend was obtained for reduced stiffness and increased torque and ROM between T0 and T1 of the paretic limbs. The Lokomat tools were able to measure the changes between paretic and non-paretic legs and the small changes between T0 and T1 measurements

NURSE-2 DoF Device for Arm Motion Guidance: Kinematic, Dynamic, and FEM Analysis

Patients with neurological or orthopedic lesions require assistance during therapies with repetitive movements. NURSE (cassiNo-qUeretaro uppeR-limb aSsistive dEvice) is an arm movement aid device for both right- and left-upper limb. The device has a big workspace to conduct physical therapy or training on individuals including kids and elderly individuals, of any age and size. This paper describes the mechanism design of NURSE and presents a numerical procedure for testing the mechanism feasibility that includes a kinematic, dynamic, and FEM (Finite Element Method) analysis. The kinematic demonstrated that a big workspace is available in the device to reproduce therapeutic movements. The dynamic analysis shows that commercial motors for low power consumption can achieve the needed displacement, acceleration, speed, and torque. Finite Element Method showed that the mechanism can afford the upper limb weight with light-bars for a tiny design. This work has led to the construction of a NURSE prototype with a light structure of 2.6 kg fitting into a box of 35 × 45 × 30 cm. The latter facilitates portability as well as rehabilitation at home with a proper follow-up. The prototype presented a repeatability of ±1.3 cm that has been considered satisfactory for a device having components manufactured with 3D rapid prototyping technology