Azalée is a French company, founded in 2012, which develops an innovative technology for assessing the characteristics of the cortical bone
The VOG* (Vitesse des Ondes Guidées) technology is based on the measurement of ultrasonic guided modes in the cortical part of the bone that behaves as a waveguide.
It allows non-invasive measurement of cortical thickness and porosity in the arm (radius) and leg (tibia).
Azalée is the result of the work of the Biomedical Imaging Laboratory (INSERM CNRS/Université Pierre et Marie Curie) which conducts fundamental and applied research on morphological, functional and molecular biomedical imaging methods on small animals and humans.
Azalée is a subsidiary of Quattrocento, a company builder specialising in life sciences equipment.
*VOG technology is protected by 3 patent families
An innovative method for assessing the characteristics of cortical bone
A dedicated, multi-transmitter probe is used to generate ultrasonic waves in the cortical bone at the radius and tibia region.
Probe receivers retrieve modes guided by the cortical part of the bone.
A processing algorithm (based on singular values decomposition) has been developed to analyze the 5*24 acquisitions (5 transmitters, 24 receivers) to obtain the complete spectral image of the cortical bone.
The experimental data are then compared with a database of models. The one with the strongest correlation to measurement provides mechanical bio-markers of the bone, including cortical thickness and porosity.
The bone model developed in the laboratory has already made it possible to measure 2 relevant parameters of cortical bone, while the spectral image opens up new perspectives for analysis
In vivo measurement at radius
Q. Vallet, N. Bochud, C. Chappard, P.
Laugier, and J.-G. Minonzio, «In-vivo cortical bone characterization using guided waves measured by axial transmission,» IEEE Trans. Ultrason. Ferroelectr. Freq. Control. 63 1361 – 1371 (2016).
Reverse problem, genetic algorithms
N. Bochud, Q. Vallet, T. Bala, H. Follet, J.-G. Minonzio, and P. Laugier, “Genetic algorithms- based inversion of multimode guided waves for cortical bone characterization», Phys. Med. Biol. 61, 6953 – 6974 (2016).
Correction for attenuation
J.-G. Minonzio, J. Foiret, M. Talmant, P. Laugier, “Impact of attenuation on guided mode wavenumber measurement in axial transmission on bone mimicking plates,” J. Acoust. Soc. Am. 130, 3574-3582 (2011).
Mode measurement using SVD-based method
J.-G. Minonzio, M. Talmant, and P. Laugier, “Guided wave phase velocity measurement using multi-emitter and multi-receiver arrays in the axial transmission configuration,” J. Acoust. Soc. Am. 127, 2913-2919 (2010).
Ex vivo measurement
J. Foiret, J.-G. Minonzio, Ch. Chappard , M. Talmant, and P. Laugier, “Combined estimation of thickness and velocities using ultrasound guided waves : a feasibility study on in vitro cortical bone samples,” IEEE Trans. Ultrason. Ferroelectr. Freq. Control. 61, 1478-1488 (2014).
N. Bochud, Q. Vallet, J.-G. Minonzio, and
P. Laugier, «Predicting bone strength with ultrasonic guided waves» Scientific Reports 7, 43628 (2017).
L. Moreau , J.-G. Minonzio, J. Foiret , E. Bossy , M. Talmant, and P. Laugier, « Accurate measurement of guided modes in a plate using a bidirectional approach, » J. Acoust. Soc. Am. 135, EL15-EL21 (2014).
Correction for thickness variation
L. Moreau, J.-G. Minonzio, M. Talmant, and P. Laugier, « Measuring the wavenumber of guided modes in a thickness-varying waveguide, » J. Acoust. Soc. Am. 135, 2614 – 2625 (2014).
Pr Pascal Laugier
CNRS Research Director, LIB Director
CNRS Researcher, LIB
Professor, LIPHY, Grenoble University
CNRS Researcher, LIB
VOG technology is particularly well suited for clinical studies in osteoporosis.
A pilot trial, currently being published and aimed at predicting fracture risk, was conducted on 299 postmenopausal patients in the rheumatology department of Cochin Hospital.
VOG technology, which is non-irradiating and non-invasive, is the ideal tool for monitoring bones in children, and a pilot trial is ongoing with the Paediatrics Department of the Trousseau Hospital for the follow-up of myopathic children.
VOG technology is particularly suitable for monitoring the effects of cortical bone altering therapies such as long term corticosteroids or hormone therapies.