Sensors for HEalth Recording and Physical Activity Monitoring
Heart failure and peripheral artery disease patients require early detection of health problems in order to prevent major risk of morbidity and mortality. Evidence shows that people recover from illness or cope with a chronic condition better if they are in a familiar environment (i.e., at home) and if they are physically active (i.e., practise sports). The goal of the Sherpam project is to design, implement, and validate experimentally a monitoring system allowing biophysical data of mobile subjects to be gathered and exploited in a continuous flow.
Transmission technologies available to mobile users have been improved a lot during the last two decades, and such technologies offer interesting prospects for monitoring the health of people anytime and anywhere. The originality of project Sherpam is to rely simultaneously and in an agile way on several kinds of wireless networks in order to ensure the transmission of biometric data, while coping with network disruptions.
Project Sherpam will also developp new signal processing algorithm for activity quantification and recognition which represent now a major social and public health issue (monitoring of elderly patient, personalized quantification activity...).
The successful development and implementation of a real time system monitoring Physical Activity (PA) and estimation of Energy Expenditure (EE) for high-risk patients at home and on the move depend to a large degree on usage adoption barriers which are also studied.
In short, this project aims:
1 To develop a new generation of monitoring system that allows health monitoring at home, but also during all kinds of indoor and outdoor activities (at work, while shopping, practising sports, etc.). This monitoring system should notably be light enough to be accepted by patients during long periods, and flexible enough to accommodate several types of sensors and processing algorithms depending on the pathology considered. It should also support different kinds of wireless network technologies (e.g. 2.5G/3G/4G, personal/corporate/community Wi-Fi hotspots), and tolerate network disruptions withouth ever losing important data.
2 To improve the physiopathological follow-up of heart failure patients (HF) who could not beneficiate from cardiac resynchronization implantable therapy (clinical purposes) ; improve the recognition, quantification of Physical Activity (PA) and the estimation of energy expenditure (EE) associated with PA in healthy subjects ; and assess "in situ" the walking ability of patients with peripheral artery disease (clinical purposes). The output should monitor the breakdown in some patient's parameters (walking speed and distance, exercise intensity...).
3 To select and take into account a physiological and actimetric sensors network for physical activity quantification. Indeed, it is important to first select relevant sensors and parameters with respect to the application intended by Sherpam. Among other things, a new approach concerns the use of a magnetometer to measure lung volumes and ultimately estimating EE (Gastinger et al., 2010, 2011). Some simultaneous and embedded parameters would be monitored:
• physiological ones, in order to measure some relevant indexes of cardiac and breathing system activities,
• kinematics ones, for the global characterization of human locomotion, and more specifically the recognition and quantification of the PA and the estimation of EE related to PA.
4 To develop multi-dimensional tracking algorithms to prevent patients’ adverse events by using the communicative properties developed in this project.
5 Patients and medical staff acceptance and approval related to these new technologies that could transform patient’s care.
Project Sherpam uses sensors for data acquisition, just like project BoWI which is already supported by Labex CominLabs. However, these projects differ in several aspects, since BoWI focuses on human motion capture, while Sherpam focuses on physiological data analysis applied to two main clinical health applications. Thus, the platform developped in BoWI cannot meet the targets set in Sherpam. Regular brainstorming meetings will however be organized between both projects on:
• the management of body area networks (BAN) used for health related physiological measurements,
• the optimization of communication between BAN and data tracking centers. In addition to the applications covered by conventional systems for vital parameters monitoring, the system will allow cross applications including monitoring of PA and EE in healthy (athletes) or disabled (HF, stroke, Diabetes, Obesity, peripheral artery diseases...) populations. For daily use, the project will respectively assess the system autonomy and energy uptake. Experimental clinical protocol will be designed according to these energy constraints.
Projects Sherpam gathers research teams from several scientific domains and from several laboratories of Brittany (IRISA/CASA-Université de Bretagne Sud, LTSI-Université de Rennes 1, M2S-Université Rennes 2 and ENS Cachan, CIC-IT 1414-CHU of Rennes and LAUREPS-Université of Rennes 2), in order to constitute a pluridisciplinary research consortium able to grasp and tackle the technical as well as the societal issues raised by these applications. Each research team has already a solid experience in this domain.
Key words : m-Health, e-Health, mobile communication, wireless communication, wireless sensors, disruption-tolerant networking, opportunistic networking, Signal Processing, Data-Mining, Heart Failure, Physical activity, energy expenditure, acceptability and usage of e-health