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The objective of this paper is to develop and evaluate a directional vibrotactile feedback interface as a guidance tool for postural adjustments during work. In contrast to the existing active and wearable systems such as exoskeletons, we aim to create a lightweight and intuitive interface, capable of guiding its wearers towards more ergonomic and healthy working conditions. To achieve this, a vibrotactile device called ErgoTac is employed to develop three different feedback modalities that are able to provide a directional guidance at the body segments towards a desired pose. In addition, an evaluation is made to find the most suitable, comfortable, and intuitive feedback modality for the user. Therefore, these modalities are first compared experimentally on fifteen subjects wearing eight ErgoTac devices to achieve targeted arm and torso configurations. The most effective directional feedback modality is then evaluated on five subjects in a set of experiments in which an ergonomic optimisation module provides the optimised body posture while performing heavy lifting or forceful exertion tasks. The results yield strong evidence on the usefulness and the intuitiveness of one of the developed modalities in providing guidance towards ergonomic working conditions, by minimising the effect of an external load on body joints. We believe that the integration of such low-cost devices in workplaces can help address the well-known and complex problem of work-related musculoskeletal disorders., 12 pages. 13 figures. Now published in IEEE Transactions on Haptics DOI: 10.1109/TOH.2021.3112795

We introduce a novel approach to brain monitoring based on electroencephalogram (EEG) recordings from within the ear canal. While existing clinical and wearable systems are limited in terms of portability and ease of use, the proposed in-the-ear (ITE) recording platform promises a number of advantages including ease of implementation, minimally intrusive electrodes and enhanced accuracy (fixed electrode positions). It thus facilitates a crucial step towards the design of brain computer interfaces that integrate naturally with daily life. The feasibility of the ITE concept is demonstrated with recordings made from electrodes embedded on an earplug which are benchmarked against conventional scalp electrodes for a classic EEG paradigm.

Despite its medical relevance, accurate recognition of sedentary (sitting and lying) and dynamic activities (e.g. standing and walking) remains challenging using a single wearable device. Currently, trunk-worn wearable systems can differentiate sitting from standing with moderate success, as activity classifiers often rely on inertial signals at the transition period (e.g. from sitting to standing) which contains limited information. Discriminating sitting from standing thus requires additional sources of information such as elevation change. The aim of this study is to demonstrate the suitability of barometric pressure, providing an absolute estimate of elevation, for evaluating sitting and standing periods during daily activities. Three sensors were evaluated in both calm laboratory conditions and a pilot study involving seven healthy subjects performing 322 sitting and standing transitions, both indoor and outdoor, in real-world conditions. The MS5611-BA01 barometric pressure sensor (Measurement Specialties, USA) demonstrated superior performance to counterparts. It discriminates actual sitting and standing transitions from stationary postures with 99.5% accuracy and is also capable to completely dissociate Sit-to-Stand from Stand-to-Sit transitions.

We developed an automatic method to extract the parameters of the 7 x 50m Stroke Eficiency Test for swimming based on a wrist worn acceleration sensor device. In the wrist acceleration signal we detect characteristic swim events such as wall push-offs, wall-strikes and strokes. Based on this information we compute the distance per stroke and the swimming velocity. The upper error bounds of our automatic method are 1.67% for the velocity and 1.33% for the time per stroke. The velocity measurement accuracy is of comparable order to the manual accuracy. The automatic method clearly outperforms the manual measurement for the time per stroke extraction.

Disorders of the heart and blood vessels are the leading cause of health problems and death. Early detection of them is extremely valuable as it can prevent serious incidents (e. g. heart attack, stroke) and associated complications. This requires extending the typical mobile mon itoring methods (e.g. Holter ECG, tele-ECG) by introduction of integrated, multiparametric solutions for con tinuous monitoring of the cardiovascular system. In this paper we propose the wearable system that integrates measurements of cardiac data with actual estimation of the cardiovascular risk level. It consists of two wireless ly connected devices, one designed in the form of a necklace, the another one in the form of a bracelet (wrist watch). These devices enable contin uous measurement of electrocardiographic, plethysmographic (impedance-based an d optical-based) and accelerometric signals. Collected signals and calculated parameters indicate the elec trical and mechanical state of the heart and are processed to estimate a risk level. Depending on the risk lev el an appropriate alert is triggered and transmitted to predefined users (e.g. emergency departments, the family doct or, etc.).

Deployment of wearables for games has attracted the interest of designers and researchers both in academia and industry. However, few of these projects treat wearables as an integral part of the gameplay, often considering them as an extension of the central on-screen experience. While preliminary forays into wearable play show promise, we see a need for a rigorous design framework to illuminate the possibilities for the future of wearables for playful interaction design. In this paper we propose a Design Framework for Playful Wearables stemming from our extensive research and hands-on experience in leading four long-term game research projects incorporating wearables. We divide our framework into three high-level categories: the performative, the social and the interactive. We contend that this design space can be both a design tool for creators of wearable playful activities, as well as an analytical lens for evaluating existing wearable systems. acceptedVersion

Posture and gesture analysis and body kinematics monitoring is a field of increasing interest in bioengineering and several connected disciplines. We propose wearable systems able to read and record posture and movements of a subject wearing them. We used strain gage sensors, deposited directly onto textile fibers realizing, in contrast with different strategies, truly wearable and unintrusive systems.