Bandpass Effects in Time-Resolved Diffuse Spectroscopy

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Novel approaches to photon detection and timing for 7-wavelength time domain optical mammography

An 8-channel Silicon Photomultiplier probe and a Time-to-Digital Converter are used to build a higher-throughput, cheaper and compact detection chain for time-resolved optical mammography as compared with conventional PhotoMultiplier Tubes and Time-Correlated Single-Photon Counting boards, still providing comparable performance in the estimation of optical properties, but with higher optical responsivity

In vivo absorption spectroscopy of tumor sensitizers with femtosecond white light

A system based on a femtosecond white-light continuum and a streak camera was used for recordings of the in vivo absorption spectra of the tumor-seeking agent disulphonated aluminum phthalocyanine. Measurements for different drug doses were performed on tumor tissue (muscle-implanted adenocarcinoma) and normal muscle tissue in rats. It was found that the shape of the spectrum is tissue dependent. The peak of the absorption spectrum is blueshifted in tumor tissue as compared with the muscle. Thus the contrast in the drug-related absorption can be altered by up to a factor of 2 from the primary drug molecular-concentration contrast between normal muscle and tumor by the proper selection of the illumination wavelength

Sponges architecture by colour: new insights into the fibres morphogenesis, skeletal spatial layout and morpho-anatomical traits of a marine horny sponge species (Porifera)

This paper focuses on the skeletal architecture and morphotraits of the Mediterranean horny sponge Sarcotragus spinosulus (Demospongiae, Keratosa, Dictyoceratida, Irciniidae). This special endoskeletal system consists of a dense, variably complex connective architecture, which extends throughout the entire sponge body and is embedded in an abundant jelly-like extracellular matrix (ECM). To investigate the topographic arrangement and micro-morphotraits of these connective structures in detail and by colour, also during morphogenetic processes, histology techniques using light microscopy are essential. New information is provided on the coordinated morphogenetic processes that characterize the growth and assembly of collagenic prototype structures in the matrix of fibrous skeletal elements and drive skeleton remodelling. Our results also highlight some novelties and some remarkable peculiarities of fibrous, filamentous and fibrillar components at the levels of both composition and structure. The morphofunctional significance of skeletal architecture is suggested in the background of the anatomical complexity of S. spinosulus

Monitoring Neoadjuvant Chemotherapy Through Time Domain Diffuse Optical Spectroscopy in Breast Cancer Patients: Preliminary Clinical Results

The purpose of this clinical study is to monitor NeoAdjuvant Chemotherapy through time domain Diffuse Optical Spectroscopy, correlate the optical results with conventional imaging techniques and pathological response and eventually predict the efficacy of NAC in breast cancer patients. Our seven wavelength (635 -1060 nm) optical mammograph is used to perform non-invasive measurements on patients undergoing NAC in this study. The broad spectral range helps us to fully analyze tissue composition, that includes hemoglobin, water lipids and collagen concentration, to track the tumor response during the course of the therapy. In this paper, we present the preliminary results of five patients

Non-invasive investigation of adipose tissue by time domain diffuse optical spectroscopy

The human abdominal region is very heterogeneous and stratified with subcutaneous adipose tissue (SAT) being one of the primary layers. Monitoring this tissue is crucial for diagnostic purposes and to estimate the effects of interventions like caloric restriction or bariatric surgery. However, the layered nature of the abdomen poses a major problem in monitoring the SAT in a non-invasive way by diffuse optics. In this work, we examine the possibility of using multi-distance broadband time domain diffuse optical spectroscopy to assess the human abdomen non-invasively. Broadband absorption and reduced scattering spectra from 600 to 1100 nm were acquired at 1, 2 and 3 cm source-detector distances on ten healthy adult male volunteers, and then analyzed using a homogeneous model as an initial step to understand the origin of the detected signal and how tissue should be modeled to derive quantitative information. The results exhibit a clear influence of the layered nature on the estimated optical properties. Clearly, the underlying muscle makes a relevant contribution in the spectra measured at the largest source-detector distance for thinner subjects related to blood and water absorption. More unexpectedly, also the thin superficial skin layer yields a direct contamination, leading to higher water content and steeper reduced scattering spectra at the shortest distance, as confirmed also by simulations. In conclusion, provided that data analysis properly accounts for the complex tissue structure, diffuse optics may offer great potential for the continuous non-invasive monitoring of abdominal fat

Preliminary Evidence of the Efficacy of Time-Resolved Broad-Spectrum Optical Mammography in Monitoring Neoadjuvant Chemotherapy

We present initial results of a clinical trial involving breast cancer patients under neoadjuvant chemotherapy, monitored through our time-resolved optical mammograph. Besides hemoglobin, water and lipids, we assess collagen concentration systematically for the first time

Vastus Lateralis Muscle's Characterization on bedridden patients: a Time Domain fNIRS study

The vastus lateralis muscle was characterized by means of time-domain near infrared spectroscopy on 28 bedridden elderly patients. Optical and hemodynamics parameters were evaluated together with age, adipose tissue thickness and pennation angle