A5060063553- Optical Imaging and Spectroscopy Techniques
- Non-Invasive Vital Sign Monitoring
- Photoacoustic and Ultrasonic Imaging
- Advanced Optical Sensing Technologies
- Spectroscopy Techniques in Biomedical and Chemical Research
- Hemodynamic Monitoring and Therapy
- Infrared Thermography in Medicine
- EEG and Brain-Computer Interfaces
- Heart Rate Variability and Autonomic Control
- Spectroscopy and Laser Applications
- Muscle activation and electromyography studies
- Functional Brain Connectivity Studies
- Analytical Chemistry and Sensors
- Spectroscopy and Chemometric Analyses
- Advanced MRI Techniques and Applications
- Optical Coherence Tomography Applications
- Advanced Fluorescence Microscopy Techniques
- Traumatic Brain Injury and Neurovascular Disturbances
- Atomic and Subatomic Physics Research
- Thermoregulation and physiological responses
- Additive Manufacturing and 3D Printing Technologies
- Random lasers and scattering media
- Ocular and Laser Science Research
- Photonic and Optical Devices
- Cardiovascular and exercise physiology
Politecnico di Milano
2015-2024
Bellingham Technical College
2015
Istituto Nazionale di Fisica Nucleare, Sezione di Milano
2015
Istituto di Fotonica e Nanotecnologie
2009
Italian Institute of Technology
2009
We present a CMOS imager consisting of 32×32 smart pixels, each one able to detect single photons in the 300-900 nm wavelength range and perform both photon-counting photon-timing operations on very fast optical events with faint intensities. In mode, provides photon-number (i.e, intensity) resolved movies scene under observation, up 100 000 frames/s. photon-timing, photon arrival times 312 ps resolution. The result are videos either time-resolved (e.g., fluorescence) maps sample, or 3-D...
Performance assessment of instruments devised for clinical applications is key importance validation and quality assurance. Two new protocols were developed applied to facilitate the design optimization time-domain optical brain imaging within European project nEUROPt. Here, we present “Basic Instrumental Performance” protocol direct measurement relevant characteristics. tests are discussed in detail. First, responsivity detection system a measure overall efficiency detect light emerging...
Light is a powerful tool to non-invasively probe highly scattering media for clinical applications ranging from oncology neurology, but also molecular imaging, and quality assessment of food, wood pharmaceuticals. Here we show that, paradigmatic case diffuse optical ideal yet realistic time-domain systems yield more than 2-fold higher depth penetration many decades contrast as compared continuous-wave systems, by adopting dense source-detector distribution with picosecond time-gating....
The nEUROPt protocol is one of two new protocols developed within the European project to characterize performances time-domain systems for optical imaging brain. It was applied in joint measurement campaigns compare various instruments and assess impact technical improvements. This addresses characteristic brain detect, localize, quantify absorption changes implemented with types inhomogeneous liquid phantoms based on Intralipid India ink well-defined properties. First, small black...
We demonstrate the feasibility of time-resolved diffuse reflectance measurements at small source-detector separations using a single-photon avalanche diode operated in time-gated mode. Photon time distributions an interfiber distance 2 mm were obtained on homogeneous tissue phantom with dynamic range ${10}^{6}$ and collecting photons arrival times up to 4 ns. Moreover, we able detect local inhomogeneity deeply buried within diffusive medium better spatial resolution, higher signal intensity,...
In many time-domain single-photon measurements, wide dynamic range (more than 5 orders of magnitude) is required in short acquisition time (few seconds).We report on the results a novel technique based time-gated Single-Photon Avalanche Diode (SPAD) able to increase optical investigations.The signal acquired only well-defined intervals.Very fast 200-ps gate-ON transition used avoid undesired strong signal, which can saturate detector, hide fainter useful and reduce range.In experimental we...
We present a proof of concept prototype time-domain diffuse optics probe exploiting fast Silicon PhotoMultiplier (SiPM), featuring timing resolution better than 80 ps, tail with just 90 ps decay time-constant and wide active area 1 mm2. The detector is hosted into the used in direct contact sample under investigation, thus providing high harvesting efficiency by whole SiPM numerical aperture also reducing complexity avoiding use cumbersome fiber bundles. Our tests demonstrate accuracy...
We present the design and preliminary characterization of first detection module based on Silicon Photomultiplier (SiPM) tailored for single-photon timing applications. The aim this work is to demonstrate, thanks a suitable module, possibility easily exploit SiPM in many applications as an interesting detector featuring large active area, similarly photomultipliers tubes, but keeping advantages solid state detectors (high quantum efficiency, low cost, compactness, robustness, bias voltage,...
Diffuse correlation spectroscopy (DCS), combined with time-resolved reflectance (TRS) or frequency domain spectroscopy, aims at path length (i.e.depth) resolved, non-invasive and simultaneous assessment of tissue composition blood flow.However, while TRS provides a resolved data, the standard DCS does not.Recently, time experiment showed measurements for improved quantification respect to classical DCS, but was limited phantoms small animal studies.Here, we demonstrate in vivo studies on...
We have designed a compact dual wavelength multi-channel time-resolved system for functional near infrared spectroscopy.The enables 16 sources and up to 64 collection points, with minimum acquisition time of 5 ms per channel.Performances the been tested on tissue phantoms in terms linearity, noise, stability reproducibility.Preliminary measurements volunteers performed validate instrument capability acquire vivo maps hemodynamic parameters muscle during arterial occlusion adult head finger...
We present a novel technique for wide dynamic range optical investigations. It is based on fast-gated silicon single-photon avalanche diode (SPAD) in time-correlated counting (TCSPC) setup. The SPAD gated- <emphasis emphasistype="smcaps" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">on</emphasis> and xmlns:xlink="http://www.w3.org/1999/xlink">off </emphasis> 500 ps so as to detect photons only within given time interval. This particularly useful...
Biological signal and image processing (BSIP) constitutes a major field of interest in both educational aspects research environments biomedical engineering. In fact, the physiological knowledge improvement wide variety innovative as well implementation many clinical procedures extensively makes use these concepts more or less sophisticated medical applications. this article, important links between BSIP modeling their derived synergies are particularly stressed. support aim, examples have...
A method for the discrimination of superficial and deep absorption variations by time domain functional near infrared spectroscopy is presented. The exploits estimate photon time-dependent pathlength in different domains sampled medium makes use an approach based on time-gating distribution time-of-flights. Validation performed two-layer geometry to focus muscle head applications. Numerical simulations varied thickness upper layer, interfiber distance, shape instrument response function...
We have designed a compact dual wavelength (687 nm, 826 nm) multi-channel (16 sources, 8 detectors) medical device for muscle and brain imaging based on time domain functional near infrared spectroscopy. The system employs the space multiplexing approach to reduce cross-talk increase signal-to-noise ratio. System performances been tested homogeneous heterogeneous tissue phantoms following specifically protocols photon migration instruments. Preliminary in vivo measurements performed validate...
We present the first experimental results of reflectance Diffuse Optical Tomography (DOT) performed with a fast-gated single-photon avalanche diode (SPAD) coupled to time-correlated counting system. The Mellin-Laplace transform was employed process time-resolved data. compare performances SPAD operated in gated mode vs. non-gated for detection and localization an absorbing inclusion deeply embedded turbid medium 5 15 mm interfiber distances. demonstrate that, given acquisition time, enables...
We developed a system for acquiring 3D depth-resolved maps by measuring the Time-of-Flight (TOF) of single photons. It is based on CMOS 32 × array Single-Photon Avalanche Diodes (SPADs) and 350 ps resolution Time-to-Digital Converters (TDCs) into each pixel, able to provide photon-counting or photon-timing frames every 10 µs. show how such can be used scan large scenes in just hundreds milliseconds. Moreover, we exploit TDC unwarping refolding improving signal-to-noise ratio extending...
We present the recipe and characterization for preparing liquid phantoms that are suitable both near-infrared spectroscopy diffuse correlation spectroscopy. The have well-defined tunable optical dynamic properties, consist of a solution water glycerol with fat emulsion as scattering element. takes into account effect bulk refractive index changes due to addition glycerol, which is commonly used alter sample viscosity.
This paper presents a complete, compact, and low power consumption instrument designed for time-domain near-infrared spectroscopy. It employs two custom-designed pulsed diode lasers (operating at 830 670 nm, with average optical higher than 2 mW 40 MHz repetition frequency), single-photon detection module (based on 1 mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> active area silicon photomultiplier), custom time-to-digital converter...
We present a wearable time-domain near infrared spectroscopy (TD-NIRS) system (two wavelengths, one detection channel), which fits in backpack and performs real-time hemodynamic measurements on the brain muscle tissues of freely moving subjects. It can provide concentration values oxygenated hemoglobin (O 2 Hb), deoxygenated (HHb), total (tHb = O Hb + HHb) tissue oxygen saturation (StO ). The is battery-operated be wirelessly controlled. By following established characterization protocols...
We have devised and experimentally validated, on tissuesimulating phantoms in vivo, a time-resolved spectral fitting analysis for direct assessment of chromophore concentrations scattering parameters.Experimental data been acquired with broadband system based supercontinuum light generated photonic crystal fiber 32 channel Time Correlated Single Photon Counting system.The novel method is more robust than conventional techniques, especially at low signal-to-noise ratio.
We report on the design and first in vivo tests of a novel non-contact scanning imaging system for time-domain near-infrared spectroscopy. Our is based null source-detector separation approach utilizes polarization-selective detection fast-gated single-photon avalanche diode to record late photons only. The in-vivo included recording hemodynamics during arm occlusion two brain activation tasks. Localized non-localized changes oxy- deoxyhemoglobin concentration were detected motor cognitive...