LEUVEN & GHENT (Belgium), JAN 15, 2019 — Imec, the world-leading
research and innovation hub in nanoelectronics and digital technology
and Ghent University, together with Medtronic and other CARDIS project
partners, have developed a prototype medical device based on silicon
photonics for the screening of arterial stiffness and for the diagnosis
of cardiovascular diseases such as arterial stenosis and heart failure.
A clinical feasibility study with 100 patients has been successfully
completed by INSERM at the Georges Pompidou European Hospital in Paris,
France.
Cardiovascular disease (CVD) is among the leading causes of death
globally. Early identification of individuals at risk allows for early
intervention to halt or reverse the pathological process. Assessment of
arterial stiffness by measurement of aortic pulse wave velocity (aPWV)
is included in the latest guidelines for CVD risk prediction and it is a
key marker for hypertension. However, no tools are available today to
easily screen a large number of patients for arterial stiffness at a
GP’s office. As a consequence, many individuals remain undiagnosed.
In the Horizon 2020 project CARDIS, imec, Medtronic, and 7 other
partners, have developed a prototype mobile, low-cost, point-of-care
screening device for CVD. The device aims for measurement in a fast,
reproducible and reliable way with minimal physical contact with the
patient and minimal skills from the operator. The operating principle of
the device is Laser Doppler Vibrometry (LDV), in which a very low-power
laser is directed towards the skin overlying an artery. The skin’s
vibration amplitude and frequency, resulting from the heart beat, are
extracted from the Doppler shift of the reflected beam. The device
includes two rows of six beams, thereby scanning multiple points on the
skin above the artery in parallel.
At the heart of the system is a silicon photonics chip containing the
optical functionality of the multi-beam LDV device. The CARDIS chip was
designed by the Photonics Research Group, an imec laboratory at Ghent
University, and prototyped through imec’s silicon photonics technology
platform iSiPP50G, and has been implemented using advanced optical
packaging approaches developed at the Tyndall National Institute in
Ireland. The system has then been integrated into a handheld device and
validated for human use by Medtronic.
A clinical feasibility study at the Georges Pompidou European Hospital
in Paris has collected 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
measurement results could be obtained in all subjects. Also, the
measurement data and variability within sessions were in line with data
and variability acquired by reference techniques. A full dataset is now
available and in-depth analysis will be performed both at INSERM and at
the biomedical engineering department of Ghent University with the
support of Medtronic. Moreover, further clinical feasibility studies are
planned in the Academic Hospital of Maastricht (The Netherlands).
“The CARDIS device was well accepted by all patients, and it was
considered useful and well tolerated,” states Dr. Pierre Boutouyrie, the
cardiologist in charge of the feasibility study. “Feasibility of signal
acquisition is excellent since a useful signal was acquired in 100% of
the patients. Tolerance was excellent too, the time to get useful
signals was less than 10 min, and patients barely noticed that a
measurement was performed.”
Roel Baets, head of the Photonics Research Group (imec/UGent),
concludes: “Silicon photonics is a powerful technology that combines the
unique sensing capabilities of photonics with the low-cost and
miniaturization capabilities of silicon semiconductor technology. It’s
exciting to know that our silicon photonic chip and prototype medical
device hold the promise to change the lives of so many patients with
cardiovascular diseases.”
In a next step, a small series of the device will be produced to perform
a clinical feasibility study on a larger group of patients and over a
longer period of time. If this feasibility study demonstrates the
ability of the technology to detect cardiovascular diseases at an early
stage, high volume production can be initiated. One of the benefits of
the silicon photonics technology is that at high volumes, the chip can
be produced at low cost.
The silicon photonic chips (left) and prototype medical device (right)
to perform Laser Doppler Vibrometry on a patient’s skin to deduce
metrics for arterial stiffness and to diagnose cardiovascular diseases.
