Quentin Cassar

• Doctor of Philosophy
• University of Bordeaux

Terahertz imaging is an emerging candidate to diagnose breast cancers in a label-free manner. However, detailed terahertz analysis of early stage breast cancers is difficult to achieve owing to its low spatial resolution. In this study, utilizing a probe-less terahertz near-field microscope named scanning point terahertz source microscope, we visua...

Terahertz imaging is an emerging candidate to diagnose breast cancers in a label-free manner. However, detailed terahertz analysis of early stage breast cancers is difficult to achieve owing to its low spatial resolution. In this study, utilizing a probe-less terahertz near-field microscope named scanning point terahertz source microscope, we visua...

The usability of terahertz systems for specific inspection tasks and imaging in the aeronautics industry is assessed. Especially, we demonstrate the suitability of Frequency-modulated continuous-wave (FMCW) radars for health monitoring and see-through imaging. Additionally, terahertz time-domain data processing is performed for multi-layered paint...

Terahertz-light imaging is attracting great attention as a new approach in non-invasive/non-staining biopsy of cancerous tissues. Positively, terahertz light has been shown to be sensitive to the cell density, the hydration content, and the chemical composition of biological samples. However, the spatial resolution of terahertz imaging is typically...

This paper reports investigations led on the combination of the refractive index and morphological dilation to enhance performances towards breast tumour margin delineation during conserving surgeries. The refractive index map of invasive ductal and lobular carcinomas were constructed from an inverse electromagnetic problem. Morphological dilation...

Terahertz (THz) imaging has a potential to intraoperatively diagnose breast cancers in a label-free manner [1].

Imaging with terahertz (THz) waves has been expected as a non-invasive/non-staining visualization tool for breast cancer margins during surgeries. Breast cancer is a generic name for a heterogeneous lesion comprising invasive adenocarcinoma, in situ adenocarcinoma, most frequently in the form of ductal carcinoma in situ (DCIS) and benign tissues. U...

We report on advance developments of terahertz system data analysis for measuring the thicknesses of multiple films for non-contact control in heritage science. We provide the analysis of time-domain data regarding the measurements conducted on a French Renaissance painting realized on a copper substrate. The piece of art is made of a varnish layer...

A new method for diagnosis of diabetes mellitus is proposed, which uses for measurement a lyophilized blood plasma sample prepared in the form of a pellet. The paper develops a methodology for fast spectroscopic measurements of such pellets with terahertz pulse time-domain holography. For that reason, blood plasma pellets were experimentally measur...

The failure to accurately delineate breast tumor margins during breast conserving surgeries results in a 20% re-excision rate. Consequently, there is a clear need for an operating room device that can precisely define intraoperatively breast tumor margins in a simple, fast, and inexpensive manner. This manuscript reports investigations that were co...

Creation of the biological tissue phantoms especially breast tissue cancer in the terahertz frequency range is an actual problem of medical physics. This paper suggests using soy protein as one of the main component of breast tissue phantom instead of gelatin, as it’s water-and fat-holding substance, “quasi-bioidentical” to animal proteins and thei...

Developments toward the implementation of a terahertz pulse imaging system within a guided reflectometry configuration are reported. Two photoconductive antennas patterned on the same LT-GaAs active layer in association with a silica pipe hollow-core waveguide allowed us to obtain a guided optics-free imager. Besides working in a pulsed regime, the...

We developed a scanning laser terahertz (THz) near-field reflection imaging system using a fiber-coupled femtosecond laser source for high spatial resolution measurements without any sub-wavelength probes. In this system, THz wave pulses generated at the laser focusing spot in a non-linear optical crystal interact with a sample set on the crystal....

Terahertz time-domain spectroscopy is a specifically appropriated technique to analyze layered structure composition and dimension. Inverse electromagnetic problems are commonly solved to extract, from a recorded terahertz-signal, the distinctive layer dielectric properties and thicknesses. However, main origins and formation routes of the signal a...

Using the THz-PTDH method we have created the theoretical model and experimental set up for phase imaging of breast tissue sample and designed the image reconstruction procedure suitable for a cancer diagnostics.

We developed a scanning laser terahertz near-field reflection microscope and succeeded in getting high-spatial resolution terahertz images of breast cancer tissue. These images will help us to accurately detect canceration dynamics and tumor margins.

We report on further development of terahertz systems for measuring the thicknesses of multiple films for noncontact control in heritage science. We provide the analysis of time-domain data regarding to the measurements conducted on an ancient painting. The piece of art is made of a varnish layer deposited on the painting. The substrate is a copper...

The failure to accurately define tumor margins during breast conserving surgery (BCS) results in a 20% re-excision rate. The present paper reports the investigation to evaluate the potential of terahertz imaging for breast tissue recognition within the under-explored 300 – 600 GHz range. Such a frequency window matches new BiCMOS technology capabil...

Breast Cancer is one of the most frequently diagnosed cancer diseases worldwide, and the most common invasive tumour for women. As with all cancers, early detection plays a major role in reducing the mortality and morbidity rate. Currently, most breast cancers are detected due to clinical symptoms, or by screening mammography. The limitations of th...

Terahertz (THz) imaging and tomography are modern imaging techniques allowing 2D and 3D inspection of objects over a broadband frequency range. However, the transfer of this technique to medical applications is limited to surface or subsurface inspection due to the large concentration of water molecules which are an intrinsic characteristic of biol...

Mechanical spectroscopy gives information on the structure of solids and their relaxation mechanisms through the measurements of the elastic constants and the mechanical loss angle of materials. One common way to estimate these quantities is the resonant method where the frequency and the characteristic decay time of oscillations are measured. Sinc...