V. Petrini

Electromagnetic travel aids for visually impaired users

This paper describes the development of an electromagnetic travel aid aiming to the improvement of the mobility of blind and visually impaired subjects in unknown environments. The paper reports the preliminary results obtained with a portable prototype. They show the feasibility of the electromagnetic “cane”, the possibility to detect the presence of obstacles not detected with ordinary cane and address further improvements.

Domestic monitoring of respiration and movement by an electromagnetic sensor

The aim of this paper is to investigate the capabilities of a novel electromagnetic technique designed for contactless monitoring of breathing activity in Ambient Assisted Living applications. The method is based on the transmission of a frequency sweep and the measurement of the reflection coefficient to determine the respiration rate of a subject. To date, the method is under optimization, but it has already shown interesting capabilities of calculating not only the respiration rate, but also additional features, as the position of the subject inside a room and his/her movements. After a brief mathematical description of the algorithm, some preliminary tests will be described concerning the monitoring of a human target inside a room. These first results clearly show the capability of the method to detect the subject, his breathing rate, position and physical activity. Of course further signal processing is required in order to distinguish between different types of movements and to classify them.

Design and Realization of an Electromagnetic Guiding System for Blind Running Athletes

Nowadays the technologies aimed at improving the quality of life of people affected by visual diseases are quite common; e.g., devices to support walking or reading. Surprisingly, there is a lack of innovative technologies aimed at helping visually impaired athletes during physical activities. An example is represented by blind runners who need to be physically linked to a sighted guide by means of non-stretchable tethers during races; with consequent limitations in terms of performance and independence. This paper wants to investigate the possibility of realizing a system able to guide blind runners along a complex path, paving the way for the realization of an innovative device designed to improve their independence during training or competitions. The system consists of: (1) a mobile unit, which is placed before the runner and generates two “electromagnetic walls” delimiting the way; (2) a receiving unit (worn by the athlete) that provides vibro-tactile warnings every time the user is going outside the safe area so as to encourage him to move toward the central position. The feasibility and the utility of the system proposed are demonstrated by means of tests carried out thanks to the collaboration of a blind volunteer.

Remote Measurement of the Respiration by Electromagnetic Sensing

Respiration activity is one of the fundamental functions of the human being (also known as vital signs) which is monitored for health purposes. Often it is required to operate the sensing of the respiration activity out of hospitals or clinical environments and without contact with the patient and possibly from a distance i.e. for the home monitoring of patients or for the ambient assisted living, AAL). Unfortunately, at present the sensing apparatus for respiration monitoring purposes are mainly based on the use of contact methods (chest belt, nasal temperature transducers, etc.) which appear to be not suited for such tasks. In this paper, the authors propose a novel approach based on the use of electromagnetic sensing of the respiration activity of subject. The proposed approach provide a remote, continuous measurement of the inspiration/expiration acts of a subject without requiring a contact; these features of the proposed system are suited for domestic monitoring and AAL.

A novel measurement method for respiration rate by electromagnetic frequency sweep

The non-contact measurement of the respiration rate of a subject offers several interesting applications in hospital as well as in domestic environments. The use of electromagnetic waves has been proved to be a feasible approach to this purpose. In this paper, authors present a novel measurement method, based on the transmission of a frequency sweep and the measurement of the reflection coefficient (S11), to determine the respiration rate of the monitored subject without contact. The proposed method places itself at the half-way between continuous wave (CW) and ultra wide band (UWB) techniques, offering some advantages of both methods and improving its feasibility. Experimental tests have been carried out on voluntary subjects simultaneously measured with two reference systems in order to compare respiration frequency values. Results show a good correlation between the data measured during tests, proving that the proposed method is a valid approach to the issue of the noncontact assessment of the respiration rate both in clinical and domestic environments.

An Electromagnetic Sensor for the Autonomous Running of Visually Impaired and Blind Athletes (Part I: The Fixed Infrastructure)

Sport is one of the best ways to promote the social integration of people affected by physical disability, because it helps them to increase their self-esteem by facing difficulties and overcoming their disabilities. Nowadays, a large number of sports can be easily played by visually impaired and blind athletes without any special supports, but, there are some disciplines that require the presence of a sighted guide. In this work, the attention will be focused on marathons, during which athletes with visual disorders have to be linked to the sighted guide by means of a non-stretchable elbow tether, with an evident reduction of their performance and autonomy. In this context, this paper presents a fixed electromagnetic infrastructure to equip a standard running racetrack in order to help a blind athlete to safely run without the presence of a sighted guide. The athlete runs inside an invisible hallway, just wearing a light and a comfortable sensor unit. The patented system has been homemade, designed, realized and finally tested by a blind Paralympic marathon champion with encouraging results and interesting suggestions for technical improvements. In this paper (Part I), the transmitting unit, whose main task is to generate the two magnetic fields that delimit the safe hallway, is presented and discussed.

Multiparameter electromagnetic sensor for AAL indoor measurement of the respiration rate and position of a subject

In this paper, a new electro-magnetic sensing system for the indoor measurement of respiration rate and subject position is presented. The measurement system has been especially conceived for use in Ambient Assisted Living (AAL) applications; therefore, a specifically designed, radiation element has been designed and realized in order to be easily installed at home. The measurement principle is based on the measurement of the reflection coefficient S11 which is operated when a frequency sweep signal is transmitted by the radiation element placed in front of the subject. S11 values are related to the distance from the reflecting object (the subject) and can be consequently related to his/her respiration activity and position. A mathematical description of the algorithm for the extraction of the aimed information, the experimental set-up and some results, obtained in a real scenario (private apartment), are reported. These results clearly show the ability of the proposed sensing system to detect the presence of the subject, to measure the respiration rate and to determine his/her position within the observed environment. The proposed solution presents therefore most of the required features in order to be used for home monitoring and AAL applications.

The electromagnetic technology for safe mobility of visually impaired people

The aim of this paper is to present a survey of the activities carried out by the University Politecnica delle Marche concerning the safe mobility of visually impaired people in order to involve the control and automation community and present some hints for discussion. For this purpose, this contribution reports and discusses the use of electromagnetic (EM) systems as assistive technologies for mobility tasks of blind subjects also highlighting their advantages with respect to existing traditional electronic travel aids, in terms of performances, miniaturization, and wear ability. In particular, two applications of EM technologies will be discussed more in detail: a first example consists in the design and realization of a laboratory prototype of an EM sensor, able to detect the presence of obstacles, aimed to help visually impaired users during mobility tasks, possibly allowing them to walk safely and independently. The second example is the theoretical and experimental study of feasibility of an EM system, specifically addressed to visually impaired runners. Finally, some clues for discussion will be presented; the user interaction with the sensing system, the signal analysis and possible features extraction will be reviewed addressing issues requiring a multidisciplinary approach.

Design and realization of a wideband antenna for non-contact respiration monitoring in AAL application

This contribution is part of a wider research project whose final aim is the realization of a small EM sensing system for non-contact monitoring of respiration activity in indoor environments. The paper presents the design of an optimized radiating element that satisfies challenging requirements: good impedance matching over a wide frequency bandwidth (3-5 GHz), directive radiation pattern, small dimensions (in order to reduce its invasiveness) and low cost for realization. In detail, an antenna model already existing in literature has been optimized and adapted to this specific application using a full wave numerical simulator. Finally a first antenna prototype has been realized and experimentally tested to compare the measured parameters with the simulated results.

An electromagnetic sensor for the autonomous running of visually impaired and blind athletes (part ii: the wearable device)

Currently, the availability of technology developed to increase the autonomy of visually impaired athletes during sports is limited. The research proposed in this paper (Part I and Part II) focuses on the realization of an electromagnetic system that can guide a blind runner along a race track without the need for a sighted guide. In general, the system is composed of a transmitting unit (widely described in Part I) and a receiving unit, whose components and main features are described in this paper. Special attention is paid to the definition of an electromagnetic model able to faithfully represent the physical mechanisms of interaction between the two units, as well as between the receiving magnetic sensor and the body of the user wearing the device. This theoretical approach allows for an estimation of the signals to be detected, and guides the design of a suitable signal processing board. This technology has been realized, patented, and tested with a blind volunteer with successful results and this paper presents interesting suggestions for further improvements.