Design and development of a novel Invasive Blood Pressure simulator for patient's monitor testing

This paper presents a newly-designed and realized Invasive Blood Pressure (IBP) device for the simulation on patient’s monitors. This device shows improvements and presents extended features with respect to a first prototype presented by the authors and similar systems available in the state-of-the-art. A peculiarity of the presented device is that all implemented features can be customized from the developer and from the point of view of the end user. The realized device has been tested, and its performances in terms of accuracy and of the back-loop measurement of the output for the blood pressure regulation utilization have been described. In particular, an accuracy of ±1 mmHg at 25 °C, on a range from −30 to 300 mmHg, was evaluated under different test conditions. The designed device is an ideal tool for testing IBP modules, for zero setting, and for calibrations. The implemented extended features, like the generation of custom waveforms and the Universal Serial Bus (USB) connectivity, allow use of this device in a wide range of applications, from research to equipment maintenance in clinical environments to educational purposes. Moreover, the presented device represents an innovation, both in terms of technology and methodologies: It allows quick and efficient tests to verify the proper functioning of IBP module of patients’ monitors. With this innovative device, tests can be performed directly in the field and faster procedures can be implemented by the clinical maintenance personnel. This device is an open source project and all materials, hardware, and software are fully available for interested developers or researchers.Web of Science201art. no. 25

Measurements of generated energy/electrical quantities from locomotion activities using piezoelectric wearable sensors for body motion energy harvesting

In this paper, two different piezoelectric transducers—a ceramic piezoelectric, lead zirconate titanate (PZT), and a polymeric piezoelectric, polyvinylidene fluoride (PVDF)—were compared in terms of energy that could be harvested during locomotion activities. The transducers were placed into a tight suit in proximity of the main body joints. Initial testing was performed by placing the transducers on the neck, shoulder, elbow, wrist, hip, knee and ankle; then, five locomotion activities—walking, walking up and down stairs, jogging and running—were chosen for the tests. The values of the power output measured during the five activities were in the range 6 W–74 W using both transducers for each joint.Web of Science164art. no. 52

Sistema de adquisición de datos cinemáticos de bajo consumo

Este proyecto se plantea en la Università degli Studi Roma Tre, más concretamente en el BioLab3, laboratorio de electrónica centrado en aplicaciones biomédicas como la rehabilitación física o el alto rendimiento deportivo. Una parte fundamental en las aplicaciones para monitorizar el movimiento humano consiste en la adquisición de datos inerciales, magnéticos y dinámicos a través de sensores portátiles situados por el cuerpo. Los datos medidos por los sensores deben ser transmitidos a un dispositivo con capacidad de almacenamiento y procesado, como un PC o un smartphone. Hasta el momento, el BioLab3 enviaba los datos a través de Bluetooth clásico. La principal limitación de esa tecnología es su elevado consumo, que sumado al de los sensores limitaba notablemente la autonomía del conjunto. Surge de esta forma la necesidad de desarrollar un prototipo de adquisición y transmisión de datos inerciales y magnéticos de bajo consumo. Desde un principio se elige Bluetooth Low Energy (BLE) como alternativa, en parte por la experiencia previa del BioLab3, pero fundamentalmente por su soporte tanto en PCs como smartphones y por su elevado crecimiento en los últimos años en aplicaciones biomédicas. El proyecto parte de cero y comienza con una investigación de mercado para elegir los componentes del sistema más competitivos. En la parte de adquisición se selecciona el MPU-9250 de Invensense, un IMU (Inertial Measurement Unit) de última generación que combina un acelerómetro, un giroscopio y un magnetómetro. Para soportar la transmisión la elección se decanta por el módulo Bluetooth Low Energy BL600, de Laird Technologies, en base a su bajo consumo y reducidas dimensiones. Se ha precisado un elevado esfuerzo inicial y durante todo el proyecto de estudio de la tecnología BLE y de familiarización con el hardware y con el software de los dos extremos de comunicación. Se han diseñado placas a las que soldar cada componente para facilitar el conexionado de los pines implicados. Se ha montado cada componente en un circuito operativo, que permite además comunicar el módulo BLE y el IMU a través de una interfaz I2C. Para cargar el software en el BL600 y depurar código se ha conectado el módulo BLE al PC a través de la puerta UART y un circuito adaptador de tensiones. Una vez operativo el hardware, se han desarrollado paralelamente dos aplicaciones que intercambian datos a partir del estándar Bluetooth Low Energy: el “Servidor BLE de Adquisición de Datos” y el “Cliente BLE”. La primera aplicación se encarga de la adquisición y transmisión de datos, controlando los sensores (MPU-9250) y el módulo BLE (BL600) y se ha programado en smartBASIC (lenguaje nativo del BL600). La segunda aplicación es un sistema de visualización, procesado y almacenamiento de datos alojada en un smartphone y programada en lenguaje Java sobre sistema operativo Android. Se han transmitido con éxito los valores medidos, alcanzando así el objetivo inicial. Se han añadido mejoras no planificadas, como el control remoto del periodo de muestreo o el registro de datos en ficheros almacenados en la memoria externa del smartphone. Se ha conseguido transmitir valores a través de tres modos de comunicación BLE diferentes: indicación y lectura, donde los datos viajan desde el módulo BLE hasta el smartphone; y escritura, en cuyo caso viajan en sentido contrario. Además, se ha determinado el periodo de muestreo mínimo alcanzable, relacionándolo con un parámetro crítico de la capa BLE de enlace denominado Intervalo de Conexión. Finalmente, se ha realizado un análisis del consumo energético del sistema en función del periodo de muestreo y se ha estimado la autonomía alcanzable con pilas de botón

MEASURING REGULARITY OF FINE UPPER LIMB MOVEMENTS WITH A HAPTIC PLATFORM FOR MOTOR LEARNING AND REHABILITATION

Robot-assisted systems for arm training are being increasingly used to target moderate-to-severe upper limb impairments in rehabilitation facilities, while hand fine motor skills are seldom being targeted by these machines. This manuscript describes and tests the feasibility of a system based on a haptic interface aimed to complement the efficacy of robotic training in the rehabilitation and motor learning associated with upper extremities movements. End-effector kinematics associated with different trajectory tasks performed by 11 healthy adults were used to extract measures of smoothness, under different testing conditions that included the presence or absence of visual and haptic feedback, the use of dominant vs. non dominant hand, different shapes (crosses and circles), and the verse with which movements were done. The normalized mean square jerk, extracted from the system together with specific speed parameters, was able to capture differences in regularity between the different shapes (MSJratio significantly higher when drawing crosses, p < 1.0 E-4), and that haptic feedback significantly influences this smoothness measure (MSJratio significantly higher when haptic feedback is present, p < 5.0 E-4). The proposed system may be used as a means to monitor the progress of movement regularity in robot-mediated therapy, and the results obtained experimentally highlight the influence of haptic feedback on the smoothness of finalized upper extremity fine movements

Review of present method of glucose from human blood and body fluids assessment

The work has been aimed to create an overview of available and used methods and ways to determine the concentration of glucose in body fluids, especially from a technical point of view. It also provides an overview of the clinical features of these methods. The survey found that today's market offers a large number of options and approaches to the issue. There are accurate reference laboratory methods, self-monitoring methods for measuring glucose levels using glucometers, or continuous methods for daily monitoring of blood glucose trends and for insulin pump control. However, it must not be forgotten that the development of full closure of feedback is still not complete today. Individual methods cannot always be compared with each other, precisely because of the focus and the use of these methods. Choosing the right method of blood glucose levels in the body measuring can help patients to manage their diabetes mellitus. The methods listed in the overview are divided in terms of measurement continuity and further according to the invasiveness of the method. Finally, the issues of accuracy in the detection of glycaemia variability and the possibility of further development of these methods are discussed, as it is clear from the survey that the development is focused mainly on continuous methods improving that get to the forefront and also on developing a biosensor that is purely non-invasive and continuous.Web of Science211art. no. 11434

MEASURING REGULARITY OF FINE UPPER LIMB MOVEMENTS WITH A HAPTIC PLATFORM FOR MOTOR LEARNING AND REHABILITATION

Robot-assisted systems for arm training are being increasingly used to target moderate-to-severe upper limb impairments in rehabilitation facilities, while hand fine motor skills are seldom being targeted by these machines. This manuscript describes and tests the feasibility of a system based on a haptic interface aimed to complement the efficacy of robotic training in the rehabilitation and motor learning associated with upper extremities movements. End-effector kinematics associated with different trajectory tasks performed by 11 healthy adults were used to extract measures of smoothness, under different testing conditions that included the presence or absence of visual and haptic feedback, the use of dominant vs. non dominant hand, different shapes (crosses and circles), and the verse with which movements were done. The normalized mean square jerk, extracted from the system together with specific speed parameters, was able to capture differences in regularity between the different shapes (MSJratio significantly higher when drawing crosses, p < 1.0 E-4), and that haptic feedback significantly influences this smoothness measure (MSJratio significantly higher when haptic feedback is present, p < 5.0 E-4). The proposed system may be used as a means to monitor the progress of movement regularity in robot-mediated therapy, and the results obtained experimentally highlight the influence of haptic feedback on the smoothness of finalized upper extremity fine movements

USING PVDF FILMS AS FLEXIBLE PIEZOELECTRIC GENERATORS FOR BIOMECHANICAL ENERGY HARVESTING

In this paper, a commercial polymeric piezoelectric film, the polyvinylidene fluoride (PVDF) was used to harvest electrical energy during the execution of five locomotion activities (walking, going down and up the stairs, jogging and running). The PVDF film transducer was placed into a tight suit in proximity of four body joints (shoulder, elbow, knee and ankle). The RMS values of the power output measured during the five activities were in the range 0.1 – 10 µW depending on the position of the film transducer on the body. This amount of electrical power allows increasing the operation time of wearable systems, and it may be used to prolong the monitoring of human vital signals for personalized health, wellness, and safety applications

Real time event-based segmentation to classify locomotion activities through a single inertial sensor

We propose an event-based dynamic segmentation technique for the classification of locomotion activities, able to detect the mid-swing, initial contact and end contact events. This technique is based on the use of a shank-mounted inertial sensor incorporating a tri-axial accelerometer and a tri-axial gyroscope, and it is tested on four different locomotion activities: walking, stair ascent, stair descent and running. Gyroscope data along one component are used to dynamically determine the window size for segmentation, and a number of features are then extracted from these segments. The event-based segmentation technique has been compared against three different fixed window size segmentations, in terms of classification accuracy on two different datasets, and with two different feature sets. The dynamic event-based segmentation showed an improvement in terms of accuracy of around 5% (97% vs. 92% and 92% vs. 87%) and 1-2% (89% vs. 87% and 97% vs. 96%) for the two dataset, respectively, thus confirming the need to incorporate an event-based criterion to increase performance in the classification of motion activities