Imaging for biology and health (IBS)

Full field optical imaging of a mouse retinal explant

Leader

Emmanuel FORT

Tel.: +33 (0)1 80 96 30 35

Co-leader

Ignacio IZEDDIN

Tel.: +33 (0)1 80 96 30 75

Permanent staff

Michael ATLAN

Tel.: +33 (0)1 80 96 30 36

Pedro BARAÇAL DE MECÊ

Tel.: +33 (0)1 80 96 30 51

Claude BOCCARA

Tel.: +33 (0)1 80 96 30 44

Maïmouna BOCOUM

Tel.: +33 (0)1 80 96 30 76

Clément CABRIEL

Tel.: +33 (0)1 80 96 30 59

Bruce DENBY

Emmanuel FORT

Tel.: +33 (0)1 80 96 30 35

Ros-Kiri ING

Tel.: +33 (0)1 80 96 30 41

Ignacio IZEDDIN

Tel.: +33 (0)1 80 96 30 75

François RAMAZ

Tel.: +33 (0)1 80 96 30 47

Olivier THOUVENIN

Tel.: +33 (0)1 80 96 30 51

News

Non-contact assessment of Cardiac Velocity profiles using Ultrasound based Surface Motion Camera: A feasibility study Sadhukhan, D., E. Saloux, C. Dorme, M. Fink, R. K. Ing, and A. Hodzic IEEE Journal of Biomedical and Health Informatics, 1-10 (2025) Abstract: Tissue Doppler imaging (TDI) mode of echocardiography plays a crucial role in diagnosing several cardiac conditions by recording the myocardial contraction velocities. To mitigate the need of experts for performing echocardiography, several studies have proposed the use of Seismocardiogram as an easier alternative to measure the cardiac timings. However, exact correlation with tissue Doppler measured cardiac velocities has not been explored. Moreover, most of the applications only use single channel contact accelerometers on the chest, thus limiting their utility. In this work, we propose the use of a novel airborne ultrasound based surface motion camera (SMC) for non-contact multichannel recording of cardiac induced surface velocities from the chest. Validation study was conducted on 30 healthy subjects with simultaneous recordings of single channel ECG along with the chest surface velocities followed by clinical Echocardiography. The SMC recorded surface velocity waveforms show correlation similarity of over 0.6 with Tissue Doppler velocity waves extracted from the echocardiographic images. Discrete time warping based distance analysis was also performed to quantify their morphological similarity. Quantitative parameters including the peak systolic velocity and amplitude ratio extracted from the chest recordings show a linear correlation (R<sup>2</sup> greater than 0.8) with that of the TDI values. Additionally, multichannel recording allows visualization of the velocity profiles on the chest and efficiently captures the spatial variations for left ventricular and septal sites. Hence, this new modality shows the potential to be a vital diagnostic technique for non-contact and robust monitoring of the cardio-mechanical functions.
Sensitivity of Lamb waves in viscoelastic polymer plates to surface contamination Spytek, J., D. A. Kiefer, R. K. Ing, C. Prada, J. Grando, and J. De Rosny Ultrasonics 149, 107571 (2025) Abstract: Detecting surface contamination on thin thermoformed polymer plates is a critical issue for various industrial applications. Lamb waves offer a promising solution, though their effectiveness is challenged by the strong attenuation and anisotropy of the polymer plates. This issue is addressed in the context of a calcium carbonate (CaCO3) layer deposited on a polypropylene (PP) plate. First, the viscoelastic properties of the PP material are determined using a genetic algorithm inversion of data measured with a scanning laser vibrometer. Second, using a bi-layer plate model, the elastic properties and thickness of the CaCO3 layer are estimated. Based on the model, the sensitivity analysis is performed, demonstrating considerable effectiveness of the A1 Lamb mode in detecting thin layers of CaCO3 compared to Lamb modes A0 and S0. Finally, a direct application of this work is illustrated through in-situ monitoring of CaCO3 contaminants using a straightforward inter-transducer measurement.
Submacular Choroidal Arteries: A Laser Doppler Holography and OCT Study Paques, M., Z. Bratasz, L. Puyo, C. Chaumette, D. Castro Farias, M. Atlan, and S. Mrejen Ophthalmology Science 5, no. 3, 100709 (2025) Abstract: Objective: To document the aspect, topography and morphometry of normal human choroidal arteries in the posterior pole by laser Doppler holography (LDH) and OCT. Design: Cross-sectional study. Subjects: Fifty-four eyes of 27 healthy subjects. Methods: A prototypic LDH system captured the laser Doppler shift of the choroidal circulation within the central 20°. Doppler shifts were filtered to extract high velocity vessels. Images of choroidal arteries identified by LDH were subsequently registered with en face and cross-sectional OCT images. Subsequently, the diameters of macular choroidal arteries and their correlation to central choroidal thickness was measured on OCT B-scans. Main Outcome Measures: Spatial disposition, distribution, and diameters of choroidal arteries. Results: Choroidal arteries were identified by LDH and OCT from their emergence from short posterior ciliary arteries (sPCAs), and could be traced to second and third divisions. In the 8 eyes that underwent LDH, 7 of 8 (88%) showed a horizontal first-order artery within 0.5 disc diameter from the fovea. OCT B-scans showed that first-order arteries were located along the sclera-choroid interface; around arteries, the choroidal tissue formed a pyramid-shaped avascular structure with a posterior base contiguous and isoreflective to the sclera. In a cohort of 49 eyes, the diameter of horizontal submacular arteries (average [± standard deviation] 136.3 μm [±47]; range, 70–209 μm) was weakly correlated to central choroidal thickness (P = 0.09). Conclusions: First-order choroidal arteries emerging from sPCAs are located along the sclerochoroidal interface and are surrounded by a pyramid-shaped avascular space, which contributes to differentiate them from veins. The majority of normal eye show a submacular first-order artery running horizontally toward the temporal periphery. These results will pave the way for a better knowledge of diseases affecting the choroidal circulation. Financial Disclosure(s): Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.
Rolling-phase dynamic full-field OCT Monfort, T., K. Grieve, and O. Thouvenin Optics Letters 50, no. 7, 2239-2242 (2025) Abstract: Dynamic full-field optical coherence tomography (DFFOCT) has recently emerged as an invaluable label-free microscopy technique, owing to its sensitivity to cell activity, as well as speed and sectioning ability. However, the quality of DFFOCT images is often degraded due to phase noise and fringe artifacts. In this work, we present a new implementation, to the best of our knowledge, named rolling-phase (RP) DFFOCT, in which the reference arm is slowly scanned over magnitudes exceeding 2π. We demonstrate mathematically and experimentally that it shows superior image quality while enabling to extract both static and dynamic contrast simultaneously. We showcase RP-DFFOCT on a macaque retinal explant and demonstrate its ability to better resolve subcellular structures, including intranuclear activity.

> All publications...

Presentation of the thematics

The IBS theme studies biological processes and tissues from the nanoscopic to the macroscopic scale. By studying in depth the interaction between different waves and biological matter, new non conventional imaging techniques are being developed. Super-resolution imaging is used to probe the organisation of matter at the single molecule scale and to understand the transport of these molecules in the cell environment, in particular in the nucleus. The full-field optical imaging team is interested in the organisation of biological tissues using label-free interferometric microscopy techniques to study the viability of organism’s cells and tissues for applications in both fundamental biology and in vivo medical diagnostics. The Holographic Doppler Imaging team develops new techniques to quantify blood flow in the retina of human patients. However, the optical approaches presented above are limited to shallow penetration depths in the human body (except from the transparent eye). In order to probe biological tissues at greater depths, it is becoming necessary to use other types of waves, in particular acoustic waves. Acousto-optic imaging enables tissue to be imaged with optical contrast at a depth of several millimetres by tagging the photons that are multiply scattered using acoustic waves. Finally, the use of acoustic waves enables the surface motion team to map vibratory deformations of the thorax in a non-contact, non-invasive manner.

Research topics

Top

The Langevin Institute

News

Research

People

Publications

Seminars & workshops

Teaching

Now hiring

Contact

Imaging for biology and health (IBS)

Leader

Co-leader

Permanent staff

News

Presentation of the thematics

Research topics

Sections