Search

[Background] bstructive failure of implanted shunts is the most common complication in the treatment of hydrocephalus. Biological material and debris accumulate in the inner walls of the valve and catheters block the normal flow of the drained cerebrospinal fluid causing severe symptoms with high morbidity and mortality. Unfortunately, at present, there is no effective preventive protocol or cleaning procedure available., [Objective] To assess whether externally applied, focused ultrasound beams can be used to resuspend deposits accumulated in brain shunts safely., [Methods] A computational model of an implanted brain shunt was implemented to test the initial design parameters of a system comprising several ultrasound transducers. Under laboratory conditions, configurations with 3 and 4 transducers were arranged in a triangle and square pattern with their radiation axis directed towards a target model of the device, 2 catheters and a brain shunt filled with water and deposited graphite powder. The ultrasound beams were then concentrated on the device across a head model., [Results] The computational model revealed that by using only 3 transducers, the acoustic field intensity on the valve was approximately twice that on the brain surface suggesting that acoustic cavitation could be selectively achieved. Resuspension of graphite deposits inside the catheters and the valve were then physically demonstrated and video-recorded with no temperature increase., [Conclusion] The technology presented here has the potential to be used routinely as a noninvasive, preventive cleaning procedure to reduce the likelihood of obstruction-related events in patients with hydrocephalus treated with an implanted shunt.

Las cámaras de vídeo pueden ser empleadas como sensores para la monitorización sin contacto en tiempo real, aplicando sobre una secuencia de fotogramas distintos algoritmos de seguimiento y extracción de bioseñales. Las características de la cámara, como la resolución, la tasa de muestreo o las bandas espectrales de la luz susceptibles de captar, son determinantes en el rendimiento de los algoritmos. Este estudio pretende ser una prueba de concepto consistente en un vehículo aéreo no tripulado con cámara RGB integrada, cuyas imágenes captadas son procesadas por dos algoritmos, uno de detección de personas (YOLOv3) basado en redes neuronales y otro de medida de tasa cardiaca (Heartbeat) basado en fotopletismografía remota. Las pruebas funcionales llevadas a cabo para validar el montaje, la detección y la medida de tasa cardiaca realizada por el prototipo muestran que la detección de personas sin contacto en tiempo real puede llevarse a cabo bajo las condiciones, dispositivos y algoritmos expuestos, pero la medida de la tasa cardiaca se ve afectada por la inestabilidad de la transmisión de fotogramas en tiempo real.

This contribution presents a two-channel inexpensive arbitrary waveform neurostimulator based on a Raspberry Pi microcomputer platform and a Howland voltage-to-current converter. The system has been designed to enable the delivery of common stimulation strategies used in visual prosthesis research.

[Objective] To conduct a proof-of-concept study of the detection of two synthetic models of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) using polarimetric imaging., [Approach] Two SARS-CoV-2 models were prepared as engineered lentiviruses pseudotyped with the G protein of the vesicular stomatitis virus, and with the characteristic Spike protein of SARS-CoV-2. Samples were prepared in two biofluids (saline solution and artificial saliva), in four concentrations, and deposited as 5-µL droplets on a supporting plate. The angles of maximal degree of linear polarization (DLP) of light diffusely scattered from dry residues were determined using Mueller polarimetry from87 samples at 405 nm and 514 nm. A polarimetric camera was used for imaging several samples under 380–420 nm illumination at angles similar to those of maximal DLP. Per-pixel image analysis included quantification and combination of polarization feature descriptors in 475 samples., [Main results] The angles (from sample surface) of maximal DLP were 3° for 405 nm and 6° for 514 nm. Similar viral particles that differed only in the characteristic spike protein of the SARS-CoV-2, their corresponding negative controls, fluids, and the sample holder were discerned at 10-degree and 15-degree configurations., [Significance] Polarimetric imaging in the visible spectrum may help improve fast, non-contact detection and identification of viral particles, and/or other microbes such as tuberculosis, in multiple dry fluid samples simultaneously, particularly when combined with other imaging modalities. Further analysis including realistic concentrations of real SARS-CoV-2 viral particles in relevant human fluids is required. Polarimetric imaging under visible light may contribute to a fast, cost-effective screening of SARS-CoV-2 and other pathogens when combined with other imaging modalities.

Effective testing is essential to control the coronavirus disease 2019 (COVID-19) transmission. Here we report a-proof-of-concept study on hyperspectral image analysis in the visible and near-infrared range for primary screening at the point-of-care of SARS-CoV-2. We apply spectral feature descriptors, partial least square-discriminant analysis, and artificial intelligence to extract information from optical diffuse reflectance measurements from 5 µL fluid samples at pixel, droplet, and patient levels. We discern preparations of engineered lentiviral particles pseudotyped with the spike protein of the SARS-CoV-2 from those with the G protein of the vesicular stomatitis virus in saline solution and artificial saliva. We report a quantitative analysis of 72 samples of nasopharyngeal exudate in a range of SARS-CoV-2 viral loads, and a descriptive study of another 32 fresh human saliva samples. Sensitivity for classification of exudates was 100% with peak specificity of 87.5% for discernment from PCR-negative but symptomatic cases. Proposed technology is reagent-free, fast, and scalable, and could substantially reduce the number of molecular tests currently required for COVID-19 mass screening strategies even in resource-limited settings.

Retinal degenerative diseases such as retinitis pigmentosa cause a progressive loss of photoreceptors that eventually prevents the affected person from perceiving visual sensations. The absence of a visual input produces a neural rewiring cascade that propagates along the visual system. This remodeling occurs first within the retina. Then, subsequent neuroplastic changes take place at higher visual centers in the brain, produced by either the abnormal neural encoding of the visual inputs delivered by the diseased retina or as the result of an adaptation to visual deprivation. While retinal implants can activate the surviving retinal neurons by delivering electric current, the unselective activation patterns of the different neural populations that exist in the retinal layers differ substantially from those in physiologic vision. Therefore, artificially induced neural patterns are being delivered to a brain that has already undergone important neural reconnections. Whether or not the modulation of this neural rewiring can improve the performance for retinal prostheses remains a critical question whose answer may be the enabler of improved functional artificial vision and more personalized neurorehabilitation strategies.

BACKGROUND: Obstructive failure of implanted shunts is the most common complication in the treatment of hydrocephalus. Biological material and debris accumulate in the inner walls of the valve and catheters block the normal flow of the drained cerebrospinal fluid causing severe symptoms with high morbidity and mortality. Unfortunately, at present, there is no effective preventive protocol or cleaning procedure available. OBJECTIVE: To assess whether externally applied, focused ultrasound beams can be used to resuspend deposits accumulated in brain shunts safely. METHODS: A computational model of an implanted brain shunt was implemented to test the initial design parameters of a system comprising several ultrasound transducers. Under laboratory conditions, configurations with 3 and 4 transducers were arranged in a triangle and square pattern with their radiation axis directed towards a target model of the device, 2 catheters and a brain shunt filled with water and deposited graphite powder. The ultrasound beams were then concentrated on the device across a head model. RESULTS: The computational model revealed that by using only 3 transducers, the acoustic field intensity on the valve was approximately twice that on the brain surface suggesting that acoustic cavitation could be selectively achieved. Resuspension of graphite deposits inside the catheters and the valve were then physically demonstrated and video-recorded with no temperature increase. CONCLUSION: The technology presented here has the potential to be used routinely as a noninvasive, preventive cleaning procedure to reduce the likelihood of obstruction-related events in patients with hydrocephalus treated with an implanted shunt.

HomeOfi es una plataforma informática que permite la interconexión entre profesionales que desean ofertar sus servicios por medio de tele consultas o venta de productos digitales, la misma posee información y datos de usuarios incluida su información bancaria, por lo que necesita considerar una estructura robusta de seguridad informática. El objetivo de esta investigación fue aplicar la Autentificación por Doble Factor para la plataforma informática HomeOfi, con el propósito de gestionar y validar la información de los usuarios, detectar y neutralizar ataques informáticos y garantizar el acceso exclusivo de sus usuarios autorizados. Para la validación de esta implementación se utilizó el método Delphi bajo las métricas de seguridad de la norma ISO 25010, para realizar este procesos se utilizaron dos ciclos, el primero sin la implementación de la Autentificación por Doble factor y el segundo con la implementación, dando como resultado en la primera interacción un cumplimento del 83% en general y en la segunda cumpliendo con un 100% de todas las métricas, mejorando así la seguridad informática de la empresa HomeOffice S.A.S.