Valentina Di Mattia

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 feasibility study of a compact radar system for autonomous walking of blind people

In this contribution, recent developments in the design and development of a novel compact smart radar for visually impaired and blind users are described. Starting from previous studies and according to the specific user requirements, a new antenna (dimensions: 54mm × 8.4mm × 1.44mm) and an integrated Tx/Rx circuit board, working in the 24-26 GHz frequency band, have been designed; the aim of these improvements is twofold: the miniaturization of the whole system allowing its integration onto a traditional white cane and a drastic reduction of the dimensions, weight and final costs of the system by using existing and available technologies.

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.

Electromagnetic Sensing of Obstacles for Visually Impaired Users

Vision impairment is a physical and sensory disability affecting a large number of subjects around the world. A large part of this subjects is aged 65 or older and their number grows faster than the overall population. In this work, a innovative sensing method, proposed by the research group of the Universita Politecnica delle Marche based on EM pulses, is presented together with some experimental results achieved in obstacles detection. The proposed approach accomplishes most of the operative requirements of electronic travel aids for visually impaired subjects and can provide additional information (height form the ground, distance and position of the obstacle) on obstacles respect to the available assistive technologies currently used by subjects affected by visual impairments.

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.

A K-band miniaturized antenna for safe mobility of visually impaired people

This contribution regards the design and realization of an electromagnetic system to support the autonomous mobility of visually impaired and blind people. The system works like a radar that transmits a short pulse and analyzes the echo coming from the surrounding. Operative tests carried out with the collaboration of a blind end user demonstrated several potentialities of the electromagnetic technology: detecting in advance (few meters from the user) dangerous objects of different shape and material, detecting the presence of obstacles located at chest or head levels, providing the position of the obstacles respect to the user, easiness of use, etc. In this context, a special attention has been paid to the miniaturization of the transmitting element, which is a k-band slot antenna to be integrated on a small circuit board to be attached onto a white cane.

An electromagnetic contactless system for apnea monitoring

The respiratory rate is one of the main vital parameters to be monitored in order to record the physiological and psychological status of a human being. In particular, apnea events represent a serious problem that affect adults and infants and can lead to irreversible brain damages and even to death. Despite these evidences, respiratory rate remains the less monitored parameter because of shortcomings of obstructive measurement techniques. For these reasons during last years we focused our research activity on the development of a smart electromagnetic sensing that allows remote and contactless breathing monitoring and reduces the request of collaboration of the monitored target. In this contribution we want to demonstrate that the electromagnetic approach proposed is also able to record long-time sleep breathing activity highlighting the presence of apnea events. To this aim a campaign of measurements have been conducted in a real domestic scenario and first interesting results will be shown together with some suggestions for future developments.

Contactless monitoring of respiratory activity using electromagnetic waves for ambient assisted living framework: feasibility study and prototype realization

Respiratory rate is a vital parameter of primary importance in medicine, sport/fitness and wellness in general, especially for most vulnerable categories of people like children and elderly people. Contactless determination of breathing activity provides a powerful and essential mean for evaluating this parameter in subjects who cannot accommodate physical sensors on their bodies. In hospital such subjects may be intensive care patients, prematurely born children and hosts of burn units. Moreover, also for long-term measurements of healthy people, for example, an elder living in home alone or in a care centre, invasive systems prove to be uncomfortable and annoying. Even for a night-time diagnosis of respiratory sleep disorders, like apnoea and hypopnoea, they demonstrate to interfere with the sleep regularity. Therefore, in the last decades many electronic devices have been conceived and realized to detect such an important parameter along with different branches of physics: strain gauges, ultrasounds, optics, thermometry, etc. This chapter presents the theoretical studies, the design and realization of a standalone Electromagnetic (EM) system for contactless determination of breathing frequency and subjects activity. Two major EM solutions are already known in the literature, continuous wave (CW) systems, and ultra-wideband (UWB) systems. The first evaluates the Doppler effect caused by the chest displacement during breathing at a single frequency, and the other one is a radar that detects the body motion by measuring the time shifts of sequential pulses.An intermediate solution thatjoins the advantages ofboth and overcomes their drawbacks is proposed. Through the use of a frequency sweep, in fact, it is possible to retrieve the equivalent information that UWB pulses are able to give, yet keeping the same contained hardware complexity of a CW system. At the same time, the proposed system proves to be robust and insensible to environmental changes. The theoretical studies have aimed at the demonstration that the solution under study helps in avoiding the blind frequencies that affect CW systems, because of sensitivity issues that depend on the variability of the reflection coefficient from the frequency and, as proved, from the harmonic content of the monitored motion. Supported by such theoretical studies, the preliminary tests are performed using laboratory instrumentation (a VNA and a commercial double ridge antenna) for a thorough campaign of measurements on assorted frequency bands, both in a controlled environment (anechoic angle) and in a concrete house, that inherently clutter the received signal. The second step involves the design and realization of a custom antenna, to be used in place of the double ridge and operating in a narrower band, which has demonstrated the same reliability of the commercial one. It has been verified in different conditions that the proposed system is able to detect both the position of the subject (i.e. distance from the antenna) and his breathing frequency, without any need for collaboration from the subject under measure. The final activity is the realization of a prototype of the device that implements the algorithms that have been studied. It is worth to highlight that the proposed system can be profitably adopted for Ambient Assisted Living framework, since it is not invasive and does not infringe the privacy of the end user, and yet it provides many valuable information about the subjects health status.