Mobile cardiac monitor to leverage silicon photonics

A new EU funded €5 million H2020 project aims to develop a silicon photonics mobile diagnostic device to identify and characterize different stages of cardiovascular diseases (CVD), including detection of stenosis and heart failure.

Led by research institute imec and Ghent University, together with Medtronic and other project partners, the H2020 project, InSiDe, will look at a path to commercializing and manufacturing the prototype device built as part of the previous CARDIS (CARdiovascular disease Detection with Integrated Silicon Photonics) project. The CARDIS project, which received around €3.6 million funding under H2020, resulted in lab validation in 2017 of a first demonstrator mobile, low-cost silicon photonics integrated laser vibrometer.

According to the World Health Organization, cardiovascular diseases are the number one cause of death globally, associated with almost 18 million deaths annually. As part of early diagnosis and intervention, monitoring changes in blood flow can be indicative of abnormalities in the way the heart contracts to pump blood as well as of changes in arterial diameter or elasticity – all potential indicators of cardiovascular disease. The EU-funded InSiDe project is developing a hand-held laser Doppler interferometer exploiting silicon photonics and efficient algorithms to deliver real-time signal analysis of selected cardiovascular parameters. This low-cost monitoring device is expected to fill an unmet need with important implications for patients and healthcare systems.

“The InSiDe project has been triggered by the remarkable outcome of the H2020 project CARDIS. Together with the CARDIS project partners, we developed a prototype mobile, affordable, point-of-care screening device for CVD. The device enables fast and reliable measurement of CVD-related biophysical signals through minimal physical contact with the patient and minimal skills from the operator,” said Roel Baets, group leader at imec and professor at Ghent University. “The objective of the InSiDe project is to take this CARDIS prototype device a major step further towards proven medical relevance and towards commercialization.”


Operating principle for CARDIS, which uses silicon photonics to monitor various parameters that would indicate cardiovascular diseases (CVD). (Image: Medtronic)

Measuring heartbeat using Doppler shift

The operating principle of the device is laser Doppler vibrometry (LDV): a low-power laser is directed towards the skin overlying an artery. The skin’s vibration amplitude and frequency, resulting from the heartbeat, are extracted from the Doppler shift of the reflected beam. The key underlying technology is silicon photonics, which allows the implementation of advanced optical functionality in a chip produced in a CMOS fab environment.

The CARDIS prototype device underwent a first clinical feasibility study at the Georges Pompidou European Hospital in Paris (France) and at the Academic Hospital of Maastricht (The Netherlands), collecting a substantial clinical dataset, both from healthy subjects as well as from patients with cardiovascular conditions. The quality of the device readings was found to be very good and adequate biophysical signals could be obtained in all subjects, even if the algorithmic translation to relevant markers for medical pathologies needs further work.

As a result, Baets added, “The very promising results from the CARDIS project stimulated the consortium to take the next step and aim at bringing the prototype to a true manufacturable product that is useful for GPs and cardiologists in their daily practice.”

To bring the CARDIS prototype device towards commercialization, the InSiDe project will develop a handheld clinical, battery-operated investigational device capable of measuring, quantifying and recording cardiovascular conditions; develop algorithms to translate the interferometer signals into data that are relevant to monitor and diagnose a number of cardiovascular diseases (CVDs); and demonstrate in clinical feasibility studies the usefulness of the device for GPs and cardiologists.


The new project aims to develop a bath to commercialization of the optical subsystems and components for the handheld (Image: Medtronic)

This will involve investigating, designing and fabricating optical subsystems and components including a photonic integrated chip (PIC) with a multi-branch laser interferometer and integrated photo detectors plus input port for an external micro-optical laser assembly; a micro-optical laser assembly; and a micro-optical lens system. They will then look at integrating the subsystems and building a multi-beam interferometric laser vibrometer.

Under the four-year project, InSiDe will also develop a process flow scalable to high volumes for all sub-systems and their integration steps; investigate and develop the biomechanical model to translate optical signals related to skin-level vibrations into underlying CVD physiological events; and validate the system in a clinical setting.

InSiDe is supported by the European Union’s Horizon 2020 Framework Programme for industrial leadership in information and communication technologies (H2020) and by the photonics public private partnership Photonics21. Over the next four years, InSiDe will be managed by imec, through imec’s associated laboratory located at Ghent University (the photonics research group in the Department of Information Technology). Medtronic Bakken Research Center (Netherlands) will be responsible for the scientific and technical coordination of the project.  Other industrial, academic and clinical partners will bring their expertise to the project: Ghent University (Belgium), Politecnico di Torino (Italy), Tyndall National Institute (Ireland), Microchip Technology (United Kingdom), Argotech (Czech Republic),  National Institute for Health and Medical Research – INSERM (France), Universiteit Maastricht (Netherlands) and Fundico (Belgium).

>> This article was originally published on our sister site, EE Times Europe.

 

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