The SOLUS instrument: Optical characterization of the first hand-held probe for multimodal imaging (ultrasound and multi-wavelength time-resolved diffuse optical tomography)

SOLUS is a multimodal imaging system comprising the first miniaturized handheld device to perform time domain Diffuse Optical Tomography at 8 visible and near infrared wavelengths. The hand-held probe also includes B-mode ultrasounds, Shear Wave Elastography and Color Doppler sonography, being its first goal the multiparametric non-invasive diagnosis of breast cancer. This work aims at presenting the system and its main capabilities, focusing on the optical characterization carried out to assess the overall performance of the developed photonics technologies (picosecond pulsed lasers, high-sensitive time-gated sensors and integrated electronics) and of the software for tomographic reconstructions (perturbative model based on Born approximation). Systematic measurements performed on tissue-mimicking phantoms, reproducing a perturbation (e.g., a lesion) in a homogenous background, helped understand the system efficiency range. Variations in absorption are tracked with acceptable quality, which is key to estimate tissue composition, up to 0.25 cm 1 for the bulk (relative error on average of 16 %) and 0.16 cm 1 for sufficiently big perturbations (relative error on average of 26 % for 6 cm3 inhomogeneities). Instead, the system showed low sensitivity to a localized perturbation in scattering and a relative error on average of 17 % for the scattering bulk assessment. An example case of clinical measurement is also discussed

Initial examples of the SOLUS multimodal potential

We present initial evidence of the SOLUS potential for the multimodal non-invasive diagnosis of breast cancer by describing the correlation between optical and standard radiological data and analyzing a case study

In vivo characterization of the optical and hemodynamic properties of the human sternocleidomastoid muscle through ultrasound-guided hybrid near-infrared spectroscopies

Objective. In this paper, we present a detailed in vivo characterization of the optical and hemodynamic properties of the human sternocleidomastoid muscle (SCM), obtained through ultrasound-guided near-infrared time-domain and diffuse correlation spectroscopies. Approach. A total of sixty-five subjects (forty-nine females, sixteen males) among healthy volunteers and thyroid nodule patients have been recruited for the study. Their SCM hemodynamic (oxy-, deoxy- and total hemoglobin concentrations, blood flow, blood oxygen saturation and metabolic rate of oxygen extraction) and optical properties (wavelength dependent absorption and reduced scattering coefficients) have been measured by the use of a novel hybrid device combining in a single unit time-domain near-infrared spectroscopy, diffuse correlation spectroscopy and simultaneous ultrasound imaging. Main results. We provide detailed tables of the results related to SCM baseline (i.e. muscle at rest) properties, and reveal significant differences on the measured parameters due to variables such as side of the neck, sex, age, body mass index, depth and thickness of the muscle, allowing future clinical studies to take into account such dependencies. Significance. The non-invasive monitoring of the hemodynamics and metabolism of the sternocleidomastoid muscle during respiration became a topic of increased interest partially due to the increased use of mechanical ventilation during the COVID-19 pandemic. Near-infrared diffuse optical spectroscopies were proposed as potential practical monitors of increased recruitment of SCM during respiratory distress. They can provide clinically relevant information on the degree of the patient's respiratory effort that is needed to maintain an optimal minute ventilation, with potential clinical application ranging from evaluating chronic pulmonary diseases to more acute settings, such as acute respiratory failure, or to determine the readiness to wean from invasive mechanical ventilation.</p

LOS SILOS. SANTA BRÍGIDA [Material gráfico]

Copia digital. Madrid : Ministerio de Educación, Cultura y Deporte, 201

Streptococcus agalactiae clones infecting humans were selected and fixed through the extensive use of tetracycline

Streptococcus agalactiae (Group B Streptococcus, GBS) is a commensal of the digestive and genitourinary tracts of humans that emerged as the leading cause of bacterial neonatal infections in Europe and North America during the 1960s. Due to the lack of epidemiological and genomic data, the reasons for this emergence are unknown. Here we show by comparative genome analysis and phylogenetic reconstruction of 229 isolates that the rise of human GBS infections corresponds to the selection and worldwide dissemination of only a few clones. The parallel expansion of the clones is preceded by the insertion of integrative and conjugative elements conferring tetracycline resistance (TcR). Thus, we propose that the use of tetracycline from 1948 onwards led in humans to the complete replacement of a diverse GBS population by only few TcR clones particularly well adapted to their host, causing the observed emergence of GBS diseases in neonates. \ua9 2014 Macmillan Publishers Limited. All rights reserved

Acoustic Power Transmission Through Air/Skin Interface Using a 400kHz Focused Airborne Transducer Array

International audienc

Parametric study of a thin piezoelectric cantilever for energy harvesting applications

International audienc

Bimodal ultrasonic probe comprising an optical device for diagnosis

A portable two-mode probe intended to be applied against a biological tissue to be examined, the probe comprising: an ultrasonic transducer (34, 63), configured to emit ultrasonic waves into the tissue and to receive ultrasonic waves reflected by the tissue, the transducer extending along a transverse axis; at least two optodes (32, 60, 62 a, 62 b) placed on either side of the transverse axis, such that the transducer extends between the two optodes; each optode comprising a casing (52, 61), the casing containing: a light emitter (31), configured to emit a light wave toward the tissue; and/or an optical detector (32), configured to detect a light wave scattered by the tissue; the optodes being arranged such that at least one light emitter and at least one optical detector are placed on either side of the transducer; at least one optical detector having a detection area (53, 63 a, 63 b) formed from a semiconductor and connected to a circuit board (54)

The LUCA device: a multi-modal platform combining diffuse optics and ultrasound imaging for thyroid cancer screening

We present the LUCA device, a multi-modal platform combining eight-wavelengthnear infrared time resolved spectroscopy, sixteen-channel diffuse correlation spectroscopy and a clinical ultrasound in a single device. By simultaneously measuring the tissue hemodynamics and performing ultrasound imaging, this platform aims to tackle the low specificity and sensitivit yof the current thyroid cancer diagnosis techniques, improving the screening of thyroid nodules.Here, we show a detailed description of the device, components and modules. Furthermore,we show the device tests performed through well established protocols for phantom validation,and the performance assessment forin vivo. The characterization tests demonstrate that LUCA device is capable of performing high quality measurements, with a precision in determining invivo tissue optical and dynamic properties of better than 3%, and a reproducibility of better than10% after ultrasound-guided probe repositioning, even with low photon count-rates, making it suitable for a wide variety of clinical applications