A5053761830- Optical Imaging and Spectroscopy Techniques
- Non-Invasive Vital Sign Monitoring
- Photoacoustic and Ultrasonic Imaging
- Spectroscopy Techniques in Biomedical and Chemical Research
- Infrared Thermography in Medicine
- Calibration and Measurement Techniques
- Traumatic Brain Injury and Neurovascular Disturbances
- Hemodynamic Monitoring and Therapy
- Advanced MRI Techniques and Applications
- Heart Rate Variability and Autonomic Control
- Thermoregulation and physiological responses
- EEG and Brain-Computer Interfaces
- Random lasers and scattering media
- Cardiovascular Health and Disease Prevention
- Numerical methods in inverse problems
- Functional Brain Connectivity Studies
- Spectroscopy and Chemometric Analyses
- Digital Radiography and Breast Imaging
- Neural dynamics and brain function
- Radiation Dose and Imaging
- Photoreceptor and optogenetics research
- Spectroscopy and Laser Applications
- Advanced Image Fusion Techniques
- Thermal Radiation and Cooling Technologies
- Atmospheric aerosols and clouds
Tufts University
2015-2024
National Institute of Advanced Industrial Science and Technology
1999-2003
Ministry of Economy, Trade and Industry
1999-2002
University of Electro-Communications
2002
K Lab (United States)
1999-2001
General Electric (Germany)
2000
Shimadzu (Japan)
1999
Hokkaido University
1999
Hamamatsu Photonics (Japan)
1999
University of Florence
1995-1998
Cerebral blood flow (CBF) and cerebral autoregulation (CA) are critically important to maintain proper brain perfusion supply the with necessary oxygen energy substrates. Adequate is required support normal function, achieve successful aging, navigate acute chronic medical conditions. We review general principles of CBF measurements current techniques measure based on direct intravascular measurements, nuclear medicine, X-ray imaging, magnetic resonance ultrasound techniques, thermal...
This report is the second part of a comprehensive two-part series aimed at reviewing an extensive and diverse toolkit novel methods to explore brain health function. While first focused on neurophotonic tools mostly applicable animal studies, here, we highlight optical spectroscopy imaging relevant noninvasive human studies. We outline current state-of-the-art technologies software advances, most recent impact these neuroscience clinical applications, identify areas where innovation needed,...
We present a concise overview of the modified Beer–Lambert law, which has been extensively used in literature near-infrared spectroscopy (NIRS) scattering media. In particular, we discuss one form law that is commonly found and not strictly correct. However, this incorrect still leads to correct expression for changes continuous wave optical signal associated with absorption coefficient investigated medium. Here propose notation keeps typical without introducing any assumptions.
Cerebral autoregulation (CA) is the mechanism that allows brain to maintain a stable blood flow despite changes in pressure. Dynamic CA can be quantified based on continuous measurements of systemic mean arterial pressure (MAP) and global cerebral flow. Here, we show dynamic also from local are sensitive microvasculature. We used near-infrared spectroscopy (NIRS) measure temporal oxy- deoxy-hemoglobin concentrations prefrontal cortex 11 human subjects. A novel hemodynamic model translates...
A time-resolved optical imaging system using near-infrared light has been developed. The had three pulsed sources and total 64 channels of detection, working simultaneously for acquisition the data transmitted through scattering media like biological tissues. were provided by high power picosecond diode lasers, switches directed one to object an fiber. signals reemitted from surface collected fibers, a detecting system. Each consisted attenuator, fast photomultiplier, time-correlated single...
The optical differential pathlength factor (DPF) is an important parameter for physiological measurement using near infrared spectroscopy, but the human adult head it has been available only forehead. Here we report measured DPF results forehead, somatosensory motor and occipital regions from measurements on 11 volunteers a time-resolved imaging system. optode separation was about 30 mm wavelengths used were 759 nm, 799 nm 834 nm. Measured DPFs 7.25 central forehead 6.25 temple region at For...
Because functional near-infrared spectroscopy (fNIRS) eases many of the restrictions other brain sensors, it has potential to open up new possibilities for HCI research. From our experience using fNIRS technology HCI, we identify several considerations and provide guidelines in realistic laboratory settings. We empirically examine whether typical human behavior (e.g. head facial movement) or computer interaction keyboard mouse usage) interfere with measurement fNIRS. Based on results study,...
This paper describes the Brainput system, which learns to identify brain activity patterns occurring during multitasking. It provides a continuous, supplemental input stream an interactive human-robot uses this information modify its behavior better support demonstrates that we can use non-invasive methods detect signals coming from users naturally and effortlessly generate while using computer system. If used with care, additional lead systems respond appropriately changes in user's state....
A Monte Carlo procedure has been developed to study photon migration through highly scattering nonhomogeneous media. When two scaling relationships are used, the temporal response when or absorbing inhomogeneities introduced can be evaluated in a short time from results of only one simulation carried out for homogeneous medium. Examples applications imaging defects embedded into diffusing slab, model usually used optical mammography, given. Comparisons with experimental show correctness obtained.
We introduce a multi-distance, frequency-domain, near-infrared spectroscopy (NIRS) method to measure the optical coefficients of two-layered media and thickness top layer from diffuse reflectance measurements. This features direct solution based on diffusion theory an inversion procedure Levenberg-Marquardt algorithm. have validated our through Monte Carlo simulations, experiments tissue-like phantoms, measurements forehead three human subjects. The simulations phantom shown that, in ideal...
In the field of photon migration in turbid media, different Monte Carlo methods are usually employed to solve radiative transfer equation. We consider four methods, widely used tissue optics, that based on ways build photons' trajectories. provide both theoretical arguments and numerical results showing statistical equivalence methods. we compare temporal point spread functions calculated by for a wide range optical properties slab semi-infinite medium geometry. The convergence is also...
Using diffusion theory, we show that a dual-slope method is more effective than single-slope methods or single-distance at enhancing sensitivity to deeper tissue. The requires minimum of two sources and detectors arranged in specially configured arrays. In particular, present theory results for symmetrical linear array (separated by 55 mm) sandwich 15 mm), which dual slopes achieve maximal depth about 5 mm direct current (DC) intensity (as measured continuous-wave spectroscopy) 11 phase...
We have applied functional near-infrared spectroscopy (fNIRS) to the human forehead distinguish different levels of mental workload on basis hemodynamic changes occurring in prefrontal cortex. report data 3 subjects from a protocol involving based working memory tasks. To quantify potential fNIRS for discrimination, we 3-nearest neighbor classification algorithm amplitude oxyhemoglobin ( HbO 2 ) and deoxyhemoglobin HbR concentration associated with found success rates range 44–72%, which are...
This study reports the optical characterization and quantitative oximetry of human breast cancer using spectrally-resolved images collected with a broadband, continuous-wave mammography instrument. On twenty-six patients, we two-dimensional mammograms created maps concentrations hemoglobin, water, lipids, as well oxygen saturation hemoglobin. For each cancerous breast, analyzed difference between tumor region (as identified by x-ray mammography) remainder tissue. With respect to surrounding...
We present the experimental implementation and validation of a phantom for diffuse optical imaging based on totally absorbing objects which, in previous paper [J. Biomed. Opt.18(6), 066014, (2013)], we have provided basic theory. Totally been manufactured as black polyvinyl chloride (PVC) cylinders is water dilution intralipid-20% diffusive medium India ink absorber, filled into scattering cell made PVC. By means time-domain measurements Monte Carlo simulations, shown reliability, accuracy,...
Since the initial demonstration of near-infrared spectroscopy (NIRS) for noninvasive measurements brain perfusion and metabolism in 1970s, its application to functional studies (fNIRS) 1990s, field optical has been continuously growing. Technological developments, data analysis advances, novel areas keep advancing field. In this article, we provide a view state cerebral NIRS, starting with brief historical introduction description information content NIRS signal. We argue that fNIRS should...
Abstract We present a first in vivo application of phase dual‐slopes (DSϕ), measured with frequency‐domain near‐infrared spectroscopy on four healthy human subjects, to demonstrate their enhanced sensitivity cerebral hemodynamics. During arterial blood pressure oscillations elicited at frequency 0.1 Hz, we compare three different ways analyze either intensity (I) or (ϕ) data collected the subject's forehead multiple source‐detector distances: Single‐distance, single‐slope and DS. Theoretical...