Subject-Specific and COM Acceleration-Enhanced Reflex Neuromuscular Model to Predict Ankle Responses in Perturbed Gait.

Subject-specific musculoskeletal models generate more accurate joint torque estimates from electromyography (EMG) inputs in relation to experimentally obtained torques. Similarly, reflex Neuromuscular Models (NMMs) that employ COM states in addition to musculotendon information generate muscle activations to musculoskeletal models that better predict ankle torques during perturbed gait. In this study, the reflex NMM of locomotion of one subject is identified by employing an EMG-calibrated musculoskeletal model in unperturbed and perturbed gait. A COM acceleration-enhanced reflex NMM is identified. Subject-specific musculoskeletal models improve torque tracking of the ankle joint in unperturbed and perturbed conditions. COM acceleration-enhanced reflex NMM improves ankle torque tracking especially in early stance and during backward perturbation. Results found herein can guide the implementation of reflex controllers in active prosthetic and orthotic devices.

Adaptive hybrid robotic system for rehabilitation of reaching movement after a brain injury: a usability study.

BACKGROUND: Brain injury survivors often present upper-limb motor impairment affecting the execution of functional activities such as reaching. A currently active research line seeking to maximize upper-limb motor recovery after a brain injury, deals with the combined use of functional electrical stimulation (FES) and mechanical supporting devices, in what has been previously termed hybrid robotic systems. This study evaluates from the technical and clinical perspectives the usability of an integrated hybrid robotic system for the rehabilitation of upper-limb reaching movements after a brain lesion affecting the motor function. METHODS: The presented system is comprised of four main components. The hybrid assistance is given by a passive exoskeleton to support the arm weight against gravity and a functional electrical stimulation device to assist the execution of the reaching task. The feedback error learning (FEL) controller was implemented to adjust the intensity of the electrical stimuli delivered on target muscles according to the performance of the users. This control strategy is based on a proportional-integral-derivative feedback controller and an artificial neural network as the feedforward controller. Two experiments were carried out in this evaluation. First, the technical viability and the performance of the implemented FEL controller was evaluated in healthy subjects (N = 12). Second, a small cohort of patients with a brain injury (N = 4) participated in two experimental session to evaluate the system performance. Also, the overall satisfaction and emotional response of the users after they used the system was assessed. RESULTS: In the experiment with healthy subjects, a significant reduction of the tracking error was found during the execution of reaching movements. In the experiment with patients, a decreasing trend of the error trajectory was found together with an increasing trend in the task performance as the movement was repeated. Brain injury patients expressed a great acceptance in using the system as a rehabilitation tool. CONCLUSIONS: The study demonstrates the technical feasibility of using the hybrid robotic system for reaching rehabilitation. Patients' reports on the received intervention reveal a great satisfaction and acceptance of the hybrid robotic system. TRIAL REGISTRATION: Retrospective trial registration in ISRCTN Register with study ID ISRCTN12843006 .

Simultaneous estimation of human and exoskeleton motion: A simplified protocol.

Adequate benchmarking procedures in the area of wearable robots is gaining importance in order to compare different devices on a quantitative basis, improve them and support the standardization and regulation procedures. Performance assessment usually focuses on the execution of locomotion tasks, and is mostly based on kinematic-related measures. Typical drawbacks of marker-based motion capture systems, gold standard for measure of human limb motion, become challenging when measuring limb kinematics, due to the concomitant presence of the robot. This work answers the question of how to reliably assess the subject's body motion by placing markers over the exoskeleton. Focusing on the ankle joint, the proposed methodology showed that it is possible to reconstruct the trajectory of the subject's joint by placing markers on the exoskeleton, although foot flexibility during walking can impact the reconstruction accuracy. More experiments are needed to confirm this hypothesis, and more subjects and walking conditions are needed to better characterize the errors of the proposed methodology, although our results are promising, indicating small errors.

Combining a hybrid robotic system with a bain-machine interface for the rehabilitation of reaching movements: A case study with a stroke patient.

Reaching and grasping are two of the most affected functions after stroke. Hybrid rehabilitation systems combining Functional Electrical Stimulation with Robotic devices have been proposed in the literature to improve rehabilitation outcomes. In this work, we present the combined use of a hybrid robotic system with an EEG-based Brain-Machine Interface to detect the user's movement intentions to trigger the assistance. The platform has been tested in a single session with a stroke patient. The results show how the patient could successfully interact with the BMI and command the assistance of the hybrid system with low latencies. Also, the Feedback Error Learning controller implemented in this system could adjust the required FES intensity to perform the task.

Enclavado retrógrado en fractura tibial / Retrograde nailing in a tibial fracture

Se describe un caso de fractura abierta de tibia grado iiia con gran conminución y pérdida distal de stock óseo ( cm) con total afectación de la superficie articular tibial y gran inestabilidad de la articulación peroneo-astragalina. El tratamiento realizado consintió en practicar una exhaustiva limpieza, colocándose un enclavado fresado retrógrado calcáneo-astrágalo-tibial con bloqueos proximales y distales, además de una aguja de Kirschner peroneo-astragalina. Se consiguió el cierre primario de la piel. A las 3 semanas se procedió al aporte de injerto óseo autólogo de cresta ilíaca rellenando el defecto óseo, a la reimpactación del clavo endomedular que estaba protuido distalmente y a la dinamización distal. Se consiguió la consolidación del defecto óseo en 16 semanas. Actualmente, el paciente deambula sin dolor con la artrodesis tibio-astragalina consolidada (AU)

We describe a case of a severely comminuted type iiia open tibial fracture, with distal loss of bone stock (7 cm), total involvement of the tibial joint surface, and severe instability of the fibular-talar joint. The treatment performed consisted of thorough cleansing, placing a retrograde reamed calcaneal-talar-tibial nail with proximal and distal blockage, as well as a fibular-talar Kirschner nail. Primary closure of the skin was achieved. After 3 weeks, an autologous iliac crest bone graft was performed to fill the bone defect, and the endomedullary nail, which had protruded distally was reimpacted and dynamized distally. The bone defect was eventually consolidated after 16 weeks. Currently, the patient can walk without pain the tibial-astragal arthrodesis is consolidated (AU)

[Retrograde nailing in a tibial fracture]. / Enclavado retrógrado en fractura tibial.

We describe a case of a severely comminuted type iiia open tibial fracture, with distal loss of bone stock (7 cm), total involvement of the tibial joint surface, and severe instability of the fibular-talar joint. The treatment performed consisted of thorough cleansing, placing a retrograde reamed calcaneal-talar-tibial nail with proximal and distal blockage, as well as a fibular-talar Kirschner nail. Primary closure of the skin was achieved. After 3 weeks, an autologous iliac crest bone graft was performed to fill the bone defect, and the endomedullary nail, which had protruded distally was reimpacted and dynamized distally. The bone defect was eventually consolidated after 16 weeks. Currently, the patient can walk without pain the tibial-astragal arthrodesis is consolidated.

[Brenner tumor. Report of a case and experience at the Spanish Hospital in Mexico]. / Tumor de Brenner. Presentación de un caso y experiencia en el Hospital Español de México.

Brenner tumor is a solid benign tumor of the ovary, with its origin in the parammesonephric celomic epithelium and represents about the 0.5 an the 0.79% of all ovarian tumors. We present a case of a woman in which we found a Brenner Tumor in the left ovary while we were performing an abdominal total hysterectomy. As a consequence we reviewed the experience in the Hospital Español de México in the last 10 years. We concluded that we have the same frequency of presentation that in other parts of the world. None of our cases were malignant.