Brain-machine interface based on deep learning to control asynchronously a lower-limb robotic exoskeleton: a case-of-study.

BACKGROUND: This research focused on the development of a motor imagery (MI) based brain-machine interface (BMI) using deep learning algorithms to control a lower-limb robotic exoskeleton. The study aimed to overcome the limitations of traditional BMI approaches by leveraging the advantages of deep learning, such as automated feature extraction and transfer learning. The experimental protocol to evaluate the BMI was designed as asynchronous, allowing subjects to perform mental tasks at their own will. METHODS: A total of five healthy able-bodied subjects were enrolled in this study to participate in a series of experimental sessions. The brain signals from two of these sessions were used to develop a generic deep learning model through transfer learning. Subsequently, this model was fine-tuned during the remaining sessions and subjected to evaluation. Three distinct deep learning approaches were compared: one that did not undergo fine-tuning, another that fine-tuned all layers of the model, and a third one that fine-tuned only the last three layers. The evaluation phase involved the exclusive closed-loop control of the exoskeleton device by the participants' neural activity using the second deep learning approach for the decoding. RESULTS: The three deep learning approaches were assessed in comparison to an approach based on spatial features that was trained for each subject and experimental session, demonstrating their superior performance. Interestingly, the deep learning approach without fine-tuning achieved comparable performance to the features-based approach, indicating that a generic model trained on data from different individuals and previous sessions can yield similar efficacy. Among the three deep learning approaches compared, fine-tuning all layer weights demonstrated the highest performance. CONCLUSION: This research represents an initial stride toward future calibration-free methods. Despite the efforts to diminish calibration time by leveraging data from other subjects, complete elimination proved unattainable. The study's discoveries hold notable significance for advancing calibration-free approaches, offering the promise of minimizing the need for training trials. Furthermore, the experimental evaluation protocol employed in this study aimed to replicate real-life scenarios, granting participants a higher degree of autonomy in decision-making regarding actions such as walking or stopping gait.

Emergence of SARS-CoV-2 Variants in the World: How Could This Happen?

The COVID-19 pandemic has had a significant global impact, with more than 280,000,000 people infected and 5,400,000 deaths. The use of personal protective equipment and the anti-SARS-CoV-2 vaccination campaigns have reduced infection and death rates worldwide. However, a recent increase in infection rates has been observed associated with the appearance of SARS-CoV-2 variants, including the more recently described lineage B.1.617.2 (Delta variant) and lineage B.1.1.529/BA.1 (Omicron variant). These new variants put the effectiveness of international vaccination at risk, with the appearance of new outbreaks of COVID-19 throughout the world. This emergence of new variants has been due to multiple predisposing factors, including molecular characteristics of the virus, geographic and environmental conditions, and the impact of social determinants of health that favor the genetic diversification of SARS-CoV-2. We present a literature review on the most recent information available on the emergence of new variants of SARS-CoV-2 in the world. We analyzed the biological, geographical, and sociocultural factors that favor the development of these variants. Finally, we evaluate the surveillance strategies for the early detection of new variants and prevent their distribution outside these regions.

C3 Glomerulopathy, a pathology with scarce evidence. A case report.

C3 Glomerulonephritis (C3GN) is a rare disease with an estimated incidence of 1-2 cases per million, caused by an alteration in the alternative complement pathway, although its complete physiopathology remains uncertain. Treatment evidence is poor. Immunosuppressive therapy can be initiated in more severe cases. Progression rates to end stage kidney disease are of up to 50% within a decade, and the posttransplant recurrence rates of 45-60%. We describe the case of a young man without any past medical history, with lower extremities edema, dyspnea, and kidney function deterioration. The patient was ultimately diagnosed with C3GN.

Detection of the Intention of Direction Changes During Gait Through EEG Signals.

Brain-Computer Interfaces (BCIs) are becoming an important technological tool for the rehabilitation process of patients with locomotor problems, due to their ability to recover the connection between brain and limbs by promoting neural plasticity. They can be used as assistive devices to improve the mobility of handicapped people. For this reason, current BCIs have to be improved to allow an accurate and natural use of external devices. This work proposes a novel methodology for the detection of the intention to change the direction during gait based on event-related desynchronization (ERD). Frequency and temporal features of the electroencephalographic (EEG) signals are characterized. Then, a selection of the most influential features and electrodes to differentiate the direction change intention from the walking is carried out. Best results are obtained when combining frequency and temporal features with an average accuracy of [Formula: see text]%, which are promising to be applied for future BCIs.

Selection of Spatial, Temporal and Frequency Features to Detect Direction Changes During Gait.

This paper studies the direction changes during the gait by means of two different distributions of electrodes located in the motor, premotor and occipital areas. The objective is analyzing which areas are involved in the detection of the intention of turning while the person is walking. The signals in both options are characterized with frequency and temporal features and classified following a cross-validation process. A 95% of success rate is achieved when the electrodes are disposed along the motor, premotor and occipital areas.Clinical Relevance- The objective of this study is applying the acknowledgements obtained in the designing of a brain-machine interface (BMI) based in the detection of the intention of the direction change during the gait. This BMI has clinical relevance in the rehabilitation of the gait in patients with motor injuries, assisting the patient to perform the movements as realistic as it is possible.

[Encapsulating peritoneal sclerosis]. / Diagnóstico y seguimiento de 12 casos de peritonitis esclerosante asociada a diálisis peritoneal crónica en Chile: Experience in 12 patients on peritoneal dialysis.

BACKGROUND: Encapsulating peritoneal sclerosis (EPS) is a complication of peritoneal dialysis (PD) with a low prevalence but high mortality. It is characterized by peritoneal inflammation and fibrosis with subsequent development of intestinal encapsulation. It is associated with a long lapse on PD, frequent episodes of peritonitis, high glucose solution use, and high peritoneal transport status. AIM: To report the clinical features of patients on PD, who developed EPS. MATERIAL AND METHODS: Review of medical records of 12 patients aged 43 ± 10 years (eight women) who developed EPS. RESULTS: The mean time spent on PD was 98 months. The main clinical manifestations were abdominal pain in 82% and ultrafiltration failure in 63%. In 92%, there was a history of peritonitis and 75% had high peritoneal transport at the time of diagnosis. The main findings in computed tomography were peritoneal calcification and thickening. There was a biopsy compatible with the diagnosis in 10 cases. Treatment consisted in withdrawal from PD, removal of PD catheter and the use of corticoids and tamoxifen. After withdrawal from PD 50% of patients became asymptomatic. The rest had intermittent abdominal pain and altered bowel movements. Two patients died (17%). CONCLUSIONS: EPS is a serious complication of PD, which should be suspected in any patient with compatible clinical symptoms, long time on PD, multiple episodes of peritonitis and high peritoneal transport profile.

Diagnóstico y seguimiento de 12 casos de peritonitis esclerosante asociada a diálisis peritoneal crónica en Chile: Experience in 12 patients on peritoneal dialysis / Encapsulating peritoneal sclerosis

Background: Encapsulating peritoneal sclerosis (EPS) is a complication of peritoneal dialysis (PD) with a low prevalence but high mortality. It is characterized by peritoneal inflammation and fibrosis with subsequent development of intestinal encapsulation. It is associated with a long lapse on PD, frequent episodes of peritonitis, high glucose solution use, and high peritoneal transport status. Aim: To report the clinical features of patients on PD, who developed EPS. Material and Methods: Review of medical records of 12 patients aged 43 ± 10 years (eight women) who developed EPS. Results: The mean time spent on PD was 98 months. The main clinical manifestations were abdominal pain in 82% and ultrafiltration failure in 63%. In 92%, there was a history of peritonitis and 75% had high peritoneal transport at the time of diagnosis. The main findings in computed tomography were peritoneal calcification and thickening. There was a biopsy compatible with the diagnosis in 10 cases. Treatment consisted in withdrawal from PD, removal of PD catheter and the use of corticoids and tamoxifen. After withdrawal from PD 50% of patients became asymptomatic. The rest had intermittent abdominal pain and altered bowel movements. Two patients died (17%). Conclusions: EPS is a serious complication of PD, which should be suspected in any patient with compatible clinical symptoms, long time on PD, multiple episodes of peritonitis and high peritoneal transport profile.