IMEC extends flexible ECG patch to enable arrhythmia detection

Leuven 14 July 2008In the framework of Holst Centre, IMEC has further extended the functionality of its wireless ECG patch for cardiac monitoring. It added wave analysis software locally on the patch node. The algorithm achieves excellent results for sensitivity and predictivity, and covers a broad range of wave morphologies. The innovative ECG patch is intended to monitor single-lead ECG in daily-life conditions, opening new perspectives for cardiovascular disease management. Besides technological advancements, IMEC also has teamed with National Semiconductor, a specialist in energy-efficient analogue integrated circuits, as a new partner within its Human++ programme.


IMEC's wireless ECG patch is a wearable, wire-free system easy to set up. It removes disturbances and discomfort caused by current cardiac monitoring systems. The hybrid system combines electronic assembly on flexible polyimide substrate and integration in textile. This enables flexibility in one dimension and stretchability in the other, which is required for optimal personal comfort.

The patch features IMEC's proprietary ultralow-power biopotential ASIC - application specific integrated circuit - to extract the bio-potential signals produced during the ECG measurements, a commercial micro-controller and a 2.4GHz radio link. The patch can continuously monitor the patient's heart at a sample rate of up to 1KHz. It sends the results directly to the receiver, or it can analyse the signals locally before sending them. Local analysis reduces the use of the radio, improving the autonomy of the patch. The current autonomy with local delineation is 10 days of continuous monitoring.

IMEC's smart ECG patch which enables comfortable arrhythmia detection in daily life. Photo: Courtesy of IMEC, Leuven, Belgium.

The algorithm embedded in the system performs the delineation of the ECG signal, i.e. the detection of the important electrical waves from the heart. The delineator is able to identify P,Q, R, S, and T wave peaks and boundaries. Since the intervals and amplitudes of these waves contain most of the useful information of the ECG, this delineation will provide quick and useful information to the health care provider.

Flexible core of IMEC's smart ECG patch. Photo: Courtesy of IMEC, Leuven, Belgium.

The delineator on the ECG patch has been validated over all the recordings in the MIT QT database - a database developed by MIT which includes ECGs chosen to represent a wide variety of QRS and ST-T morphologies, in order to challenge QT detection algorithms with real-world variability. IMEC's ECG patch achieves a 99,93 percent sensitivity and a 98,28 percent positive predictivity for QRS detection on 86.994 beats. For delineation over 3623 beats, it reaches a 99,83 percent sensitivity and a 95,08 percent positive predictivity.

IMEC's Human++ programme develops technology for wireless autonomous sensor systems that can be used for health and wellness monitoring. Such systems will for example enable analysis of people with sleep apnea from home or monitor epilepsy patients in an ambulatory setting. The programme was launched in 2002 and got a considerable boost in 2005 when IMEC decided to house it in Holst Centre, a new research centre set up together with the Dutch research institute TNO under impulse of the Dutch government.

National Semiconductor recently joined the Human++ programme. Other Holst Centre partners include Alcatel-Lucent, ASML, Bekaert, NXP, Philips, Target Compiler Technologies and Texas Instruments. Bert Gyselinckx, Human++ programme director, stated: "We see that the Human++ technical progress is reflected in a growing industrial interest. Our physiological monitoring systems are based on ultra-low power wireless communication and start to make use of innovative energy harvesting technology. They are finding applications in sleep staging analysis, cardiac arrhythmia detection and epilepsy monitoring. The growing interest from industry worldwide is proven by new partnerships."

Holst Centre is an independent open-innovation R&D centre that develops generic technologies for Wireless Autonomous Transducer Solutions and for Systems-in-Foil. A key feature of Holst Centre is its partnership model with industry and academia around shared roadmaps and programmes. It is this kind of cross-fertilization that enables Holst Centre to tune its scientific strategy to industrial needs.

Holst Centre was set up in 2005 by IMEC in Flanders, Belgium and TNO, The Netherlands, with support from the Dutch Ministry of Economic Affairs and the Government of Flanders. It is named after Gilles Holst, a Dutch pioneer in Research and Development and first director of Philips Research. Located on the High Tech Campus in Eindhoven, Holst Centre benefits from the state-of-the-art on-site facilities. Holst Centre has over 100 employees, growing to over 200 by 2010, and a commitment from over 15 industrial partners.

IMEC is a world-leading independent research centre in nano-electronics and nanotechnology. IMEC vzw is headquartered in Leuven, Belgium, and has a sister company in the Netherlands, IMEC-NL, offices in the United States, China and Taiwan, and representatives in Japan. Its staff of more than 1600 people includes more than 500 industrial residents and guest researchers. In 2007, its revenue (P&L) was 244,5 million euro.

IMEC's More than Moore research aims at semiconductor scaling towards sub-32nm nodes. With its More than Moore research, IMEC looks into technologies for nomadic embedded systems, wireless autonomous transducer solutions, biomedical electronics, photovoltaics, organic electronics and GaN power electronics.

IMEC's research bridges the gap between fundamental research at universities and technology development in industry. Its unique balance of processing and system know-how, intellectual property portfolio, state-of-the-art infrastructure and its strong network worldwide position IMEC as a key partner for shaping technologies for future systems.

Leslie Versweyveld

[Medical IT News][Calendar][Virtual Medical Worlds Community][News on Advanced IT]