Tyndall National Institute is one of Europe's leading research centres, specialising in Information and Communications Technology (ICT) hardware. Tyndall has a critical mass of over 360 researchers, engineers, students and support staff placing a particular emphasis on quality, accomplishment and the delivery to Ireland of value from research. Tyndall’s areas of expertise range from micro-nanolectronics, microsystems, and photonics to theory modeling supported by a central fabrication facility.
(Optical Society of America, 2018-01) Li, Yanlu; Greenwald, Stephen; Tommasin, Daniela; Zhu, Jinghao; Segers, Patrick; Aasmul, Soren; de Melis, Mirko; Duperron, Matthieu; O'Brien, Peter; Schüler, Ralf; Baets, Roel; Horizon 2020
A miniaturized 2×6-beam laser Doppler vibrometry sensor for non-invasive detection of cardiovascular disease is demonstrated. The pulse wave velocity is retrieved from preliminary experiments both on phantoms and on human subjects.
(Optical Society of America, 2020-06-22) Li, Yanlu; Marais, Louise; Khettab, Hakim; Quan, Zhiheng; Aasmul, Soren; Leinders, Rob; Schüler, Ralf; Morrissey, Padraic E.; Greenwald, Stephen; Segers, Patrick; Vanslembrouck, Michael; Bruno, Rosa M.; Boutouyrie, Pierre; O'Brien, Peter; de Melis, Mirko; Baets, Roel; Horizon 2020
Pulse wave velocity (PWV) is a reference measure for aortic stiffness, itself an important biomarker of cardiovascular risk. To enable low-cost and easy-to-use PWV measurement devices that can be used in routine clinical practice, we have designed several handheld PWV sensors using miniaturized laser Doppler vibrometer (LDV) arrays in a silicon photonics platform. The LDV-based PWV sensor design and the signal processing protocol to obtain pulse transit time (PTT) and carotid-femoral PWV in a feasibility study in humans, are described in this paper. Compared with a commercial reference PWV measurement system, measuring arterial pressure waveforms by applanation tonometry, LDV-based displacement signals resulted in more complex signals. However, we have shown that it is possible to identify reliable fiducial points for PTT calculation using the maximum of the 2nd derivative algorithm in LDV-based signals, comparable to those obtained by the reference technique, applanation tonometry.
(Optical Society of America, 2018) Li, Yanlu; Zhu, Jinghao; Duperron, Matthieu; O'Brien, Peter A.; Schüler, Ralf; Aasmul, Soren; de Melis, Mirko; Kersemans, Mathias; Baets, Roel; Horizon 2020
This paper describes an integrated six-beam homodyne laser Doppler vibrometry (LDV) system based on a silicon-on-insulator (SOI) full platform technology, with on-chip photo-diodes and phase modulators. Electronics and optics are also implemented around the integrated photonic circuit (PIC) to enable a simultaneous six-beam measurement. Measurement of a propagating guided elastic wave in an aluminum plate (speed ≈≈ 909 m/s @ 61.5 kHz) is demonstrated.
(Institute of Electrical and Electronics Engineers (IEEE), 2018-05) Li, Yanlu; Zhu, Jinghao; Duperron, Matthieu; O'Brien, Peter A.; Schüler, Ralf; Aasmul, Soren; De Melis, Mirko; Baets, Roel; Horizon 2020
A compact six-beam homodyne laser Doppler vibrometry (LDV) system is realized based on a silicon-on-insulator (SOI) photonic integrated circuit. We demonstrate a speckle mitigation method by averaging signals from the six channels.