Jimena Rodríguez

Real-time classification of ECGs on a PDA

The new advances in sensor technology, personal digital assistants (PDAs), and wireless communications favor the development of a new type of monitoring system that can provide patients with assistance anywhere and at any time. Of particular interest are the monitoring systems designed for people that suffer from heart arrhythmias, due to the increasing number of people with cardiovascular diseases. PDAs can play a very important role in these kinds of systems because they are portable devices that can execute more and more complex tasks. The main questions answered in this paper are whether PDAs can perform a complete electrocardiogram beat and rhythm classifier, if the classifier has a good accuracy, and if they can do it in real time. In order to answer these questions, in this paper, we show the steps that we have followed to build the algorithm that classifies beats and rhythms, and the obtained results, which show a competitive accuracy. Moreover, we also show the feasibility of incorporating the built algorithm into the PDA.

ANTARCTICA: A Multiagent System for Internet Data Services in a Wireless Computing Framework

Nowadays, the widespread use of wireless devices that can be connected to Internet allows users to access information from anywhere and at anytime. However, the management of Internet data services makes users of wireless devices face certain problems such as the inestability of the used media, the lack of suitability of existing services to the limited capabilities of some wireless devices (e.g., in the visualization of GUIs) and the high cost that their use implies. In this paper, we present the general features of ANTARCTICA, a system which provides users of wireless devices with a new environment to achieve their data management needs. The ANTARCTICA system is based on the use of proxies and agent technology and presents the following main features: 1) multiplicity, managing multiple data services, 2) scalability, allowing one to incorporate new services, 3) efficiency, optimizing wireless communications, 4) flexibility, supporting the mobility of users without restrictions, and 5) simplicity, making technical issues transparent to the users. We also report on the implementation of some services supported by ANTARCTICA and present experimental results associated to them.

An Innovative System that Runs on a PDA for a Continuous Monitoring of People

Continuous pervasive monitoring has the potential to improve the quality of life of many persons (for example those who suffer from heart arrhythmias or elderly people who suffer from chronic diseases). We show the three main steps related to the monitoring process and supported by our system. First, how data are captured by sensors which send those data using wireless communications to a PDA (personal digital assistant). Second, how data are analyzed, locally on the PDA, using techniques proposed in the areas of the semantic Web and machine learning. Finally, how data stored at the PDA can be queried remotely using Web services. Those three steps are illustrated in two different scenarios that the system can deal with: tele-assistance and monitoring of arrhythmias. Moreover, through the paper we highlight the main advantages provided by the system: active monitoring which consists in reacting to anomalous situations without direct intervention of the user; universal assistance, i.e. irrespective of time or place through the use of wireless communications and PDAs; vital signs monitoring which consists in using sensors that capture the value of those vital signs, and subsequently feed them to a decision support system that analyses them and generates an alarm if necessary; and remote monitoring which allows authorized personal to consult data on monitored patients, using the Internet. Finally we present some performance results which demonstrate the feasibility of the system

Architecture, cost-model and customization of real-time monitoring systems based on mobile biological sensor data-streams

Innovation in the fields of wireless data communications, mobile devices and biosensor technology enables the development of new types of monitoring systems that provide people with assistance anywhere and at any time. In this paper we present an architecture useful to build those kind of systems that monitor data streams generated by biological sensors attached to mobile users. We pay special attention to three aspects related to the system efficiency: selection of the optimal granularity, that is, the selection of the size of the input data stream package that has to be acquired in order to start a new processing cycle; the possible use of compression techniques to store and send the acquired input data stream and; finally, the performance of a local analysis versus a remote one. Moreover, we introduce two particular real systems to illustrate the suitability and applicability of our proposal: an anywhere and at any time monitoring system of heart arrhythmias and an apnea monitoring system.

A Wireless Application That Monitors ECG Signals On-Line: Architecture and Performance

In this paper, we present an innovating on-line monitoring system that has been developed by applying new advances in biosensors, mobile devices and wireless technologies. The aim of the system is to monitor people that suffer from heart arrhythmias without having to be hospitalized; and therefore, living a normal life while feeling safe at the same time. On the one hand, the architecture of the system is presented; and, on the other hand, some performance results and implementation details are explained showing how the previous solution can be effectively implemented and deployed into a system that makes use of PDAs, and wireless communications: Bluetooth and GPRS. Moreover, special attention is paid to two aspects: cost of the wireless communications and notification latency for the detected serious heart anomalies.

Capturing, Analysing, and Managing ECG Sensor Data in Handheld Devices

The new advances in sensor technology, PDAs and wireless communication favour the development of monitoring systems. In this context we have developed MOLEC, a system that monitors people that suffer from heart arrhythmias. It carries out three tasks: a) it captures the digital data sent by different sensors and transforms them into a concrete format; b) it analyses the ECG data sent by the PDA sensors to locally detect anomalous situations as soon as possible; c) it manages ECG data in the following way: 1) normal ECG data are stored in files and are sent compressed to a hospital, within a certain time granularity; and 2) when anomalous ECG data are identified an alarm is sent to the hospital; and also these anomalous ECG are stored at the PDA database. Data in that database can be queried, locally or remotely, in order to know different aspects that can be related to anomalous situations.

Real-Time Monitoring of Mobile Biological Sensor Data-Streams: Architecture and Cost-Model

In this paper an architecture useful to build systems that monitor data streams generated by biological sensors attached to mobile users is presented. In order to illustrate the suitability and applicability of our proposal, we introduce two particular real systems: an anywhere and at any time monitoring system of heart arrhythmias and a portable and light system that monitor sleep apneas. We also propose a cost model that takes into account three aspects related to the system efficiency: selection of the optimal granularity, that is, the selection of the size of the input data stream package that has to be acquired in order to start a new processing cycle; the possible use of compression techniques to store and send the acquired input data stream and; finally, the performance of a local analysis versus a remote one.

MOLEC: anywhere and at any time arrhythmia classification

The new advances in sensor technology, PDAs and wireless communications favor the development of a new type of monitoring systems that can provide patients with assistance anywhere and at any time. Of particular interest are the monitoring systems designed for people that suffer from heart arrhythmias, due to the increasing number of people with cardiovascular diseases. In this paper, we present MOLEC: a PDA-based system that performs local real-time classification and detects the ECG anomalies in situ. In the actual implementation of MOLEC, the signal is acquired by some ECG sensors (ActiveECG sensors) with a 360 Hz frequency. For the preprocessing of the signal the ECGPUWAVE tool and an automata developed by us that identifies the beats are used. We have also developed a beat and rhythm classifiers that determine if there has been an anomalous rhythm, and in that case, an alarm is sent to a hospital via wireless communications. The rhythm detection delay of the MOLEC system is of 6.66 seconds

An on-line ischemia monitoring algorithm for mobile devices

The early diagnosis of ischemic events may prevent irreversible damage to the heart muscle. Mobile devices like PDAs provided with wireless communication links are being used successfully in order to build on line monitoring systems. The aim of this paper is to show an ischemia classifier with high rates of sensitivity and positive predictivity and also able to run in real time that can be implemented on a mobile device like a PDA. The LTST database (43 recordings version) has been used to develop and validate the results of the classifier, considering the ischemic and heart rate related events together. The sensitivity of the classifier is 80.65% for episodes annotated according to C protocol and the positive predictivity is 73.11% for episodes annotated according to A protocol in the LTST database