Estimation of optical pathlength through tissue from direct time of flight measurement

1988/12/01 by D T Delpy, David T. Delpy, M Cope +9 · 2,256 citations
Engineering · Mathematics · Medicine · #Imaging phantom #Laser #Materials science #Mathematics #Monte Carlo method #Near-infrared spectroscopy #Non-Invasive Vital Sign Monitoring #Optical Imaging and Spectroscopy Techniques #Optics #Photoacoustic and Ultrasonic Imaging #Physics #Picosecond #Scattering #Statistics #Time of flight

paper · doi:10.1088/0031-9155/33/12/008

published in Physics in Medicine and Biology 33(12), 1433-1442 (IOP Publishing)

openalex publication_date 1988/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/06

Abstract

Quantitation of near infrared spectroscopic data in a scattering medium such as tissue requires knowledge of the optical pathlength in the medium. This can now be estimated directly from the time of flight of picosecond length light pulses. Monte Carlo modelling of light pulses in tissue has shown that the mean value of the time dispersed light pulse correlates with the pathlength used in quantitative spectroscopic calculations. This result has been verified in a phantom material. Time of flight measurements of pathlength across the rat head give a pathlength of 5.3 +/- 0.3 times the head diameter.

Cited by

• Effect of lingual gauze swab placement on pulse oximeter readings in anaesthetised dogs and cats
• Non-invasive optical spectroscopy and imaging of human brain function
• Hemodynamic correlates of spontaneous neural activity measured by human whole-head resting state EEG + fNIRS
• A comprehensive overview of diffuse correlation spectroscopy: Theoretical framework, recent advances in hardware, analysis, and applications
• Individual abilities to estimate levels of movement synchrony predict action observation network activation
• Awareness of embodiment enhances enjoyment and engages sensorimotor cortices
• Best practices for fNIRS publications
• HRfunc: a tool for modeling hemodynamic response variability in fNIRS
• Beer–Lambert law for optical tissue diagnostics: current state of the art and the main limitations
• Characterizing developmental changes in infant habituation using functional change point detection
• Pleasant walking environments enhance emotional experiences and reduce brain activation - an application of fNIRS in urban studies
• Users evaluating physical, virtual, and mixed reality prototypes exhibit differential DLPFC brain activity
• The neuropsychophysiological correlates of compassion: A transcranial direct current stimulation (tDCS) study
• Inferior Parietal Lobe Activity Reveals Bimanual Coupling and Interference
• DL-QC-fNIRS: a deep learning tool for automated quality control in functional near-infrared spectroscopy signals
• Maternal anxiety shapes prediction error responses in the infant brain
• Accuracy of Noninvasive Glucose Sensing Based on Near-Infrared Spectroscopy
• Near-Infrared Spectroscopy to Assess Covert Volitional Brain Activity in Intensive Care
• Commonality and specificity of acupuncture tonifying-reducing manipulations based on functional near-infrared spectroscopy
• Exploring gait automaticity and prefrontal brain activity during single and dual-task walking in aging and Parkinson’s disease
• The neural correlates of pedagogy: An fNIRS hyperscanning study of constructivist and instructivist approaches in teacher-child dyads
• Gender Moderates the Neural Impact of Problematic Media Use on Working Memory in Preschoolers: An fNIRS Study
• Comparative behavioural and neurofunctional analysis of executive functions in adults with obsessive-compulsive disorder and attention-deficit/hyperactivity disorder using a virtual reality task
• Surface-based image reconstruction optimization for high-density functional near-infrared spectroscopy
• Cross-paradigm fNIRS brain activity in 1-month-old infants across The Gambia and the United Kingdom
• Frontoparietal network activity during a combined action observation and proprioceptive stimulation protocol reveals long-term plasticity in the primary motor cortex
• On the journey to measure cognitive expertise: What can functional imaging tell us?
• A Behavioral and fNIRS Comparative Study of Gender and Task Differences in Mental Rotation Among Primary Students
• Capturing shared fNIRS responses to visual affective stimuli in young healthy women
• Feeling Positive? Predicting Emotional Image Similarity from Brain Signals
• Learnable Burst-Encodable Time-of-Flight Imaging for High-Fidelity Long-Distance Depth Sensing
• Brain Network Analysis in Alzheimer's Disease and Mild Cognitive Impairment using High-Density Diffuse Optical Tomography
• Frontal activation during a verbal-fluency task as measured by near-infrared spectroscopy
• Near infrared spectroscopy (NIRS): A new tool to study hemodynamic changes during activation of brain function in human adults
• Simultaneous measurements of cerebral oxygenation changes during brain activation by near‐infrared spectroscopy and functional magnetic resonance imaging in healthy young and elderly subjects
• Past, Present and Future of Arterial Endofibrosis in Athletes
• In Vivo Near-Infrared Spectroscopy
• Near-infrared oximetry of the brain
• Oxidative metabolism in muscle
• Performance of near-infrared spectroscopy in measuring local O2 consumption and blood flow in skeletal muscle
• Non-invasive NIR spectroscopy of human brain function during exercise
• High-Fidelity 3D Simulator for Synthetic fNIRS Data Generation
• The physics, biophysics and technology of photodynamic therapy
• Simultaneous measurements of cerebral oxygenation changes during brain activation by near-infrared spectroscopy and functional magnetic resonance imaging in healthy young and elderly subjects. [europepmc]
• Hemodynamic evoked response of the sensorimotor cortex measured noninvasively with near-infrared optical imaging. [europepmc]
• Noninvasive measurement of neuronal activity with near-infrared optical imaging. [europepmc]
• Optical brain imaging in vivo: techniques and applications from animal to man. [europepmc]
• HomER: a review of time-series analysis methods for near-infrared spectroscopy of the brain. [europepmc]
• Diffuse optical monitoring of hemodynamic changes in piglet brain with closed head injury. [europepmc]
• The effect of different anesthetics on neurovascular coupling. [europepmc]
• Improved recovery of the hemodynamic response in diffuse optical imaging using short optode separations and state-space modeling. [europepmc]
• Short separation channel location impacts the performance of short channel regression in NIRS. [europepmc]
• Quantification of the cortical contribution to the NIRS signal over the motor cortex using concurrent NIRS-fMRI measurements. [europepmc]
• Near-infrared spectroscopy: a report from the McDonnell infant methodology consortium. [europepmc]
• Diffuse optical imaging using spatially and temporally modulated light. [europepmc]
• Further improvement in reducing superficial contamination in NIRS using double short separation measurements. [europepmc]
• Motion artifacts in functional near-infrared spectroscopy: a comparison of motion correction techniques applied to real cognitive data. [europepmc]
• Continuous monitoring of brain dynamics with functional near infrared spectroscopy as a tool for neuroergonomic research: empirical examples and a technological development. [europepmc]
• Modified Beer-Lambert law for blood flow. [europepmc]
• Sensitivity of near-infrared spectroscopy and diffuse correlation spectroscopy to brain hemodynamics: simulations and experimental findings during hypercapnia. [europepmc]
• fNIRS-based brain-computer interfaces: a review. [europepmc]
• Diffuse Optics for Tissue Monitoring and Tomography. [europepmc]
• NIRS-Based Hyperscanning Reveals Inter-brain Neural Synchronization during Cooperative Jenga Game with Face-to-Face Communication. [europepmc]
• Functional Magnetic Resonance Imaging and Functional Near-Infrared Spectroscopy: Insights from Combined Recording Studies. [europepmc]
• Motion artifact detection and correction in functional near-infrared spectroscopy: a new hybrid method based on spline interpolation method and Savitzky-Golay filtering. [europepmc]
• Applications of Functional Near-Infrared Spectroscopy (fNIRS) Neuroimaging in Exercise⁻Cognition Science: A Systematic, Methodology-Focused Review. [europepmc]
• Current Status and Issues Regarding Pre-processing of fNIRS Neuroimaging Data: An Investigation of Diverse Signal Filtering Methods Within a General Linear Model Framework. [europepmc]
• Best practices for fNIRS publications. [europepmc]

Related

• A review on time domain diffuse optics: principles and applications on human biological tissues
• Theoretical prediction of the source-detector separation distance suited to the application of the spatially resolved spectroscopy from the near-infrared attenuation data cube of tissues
• Monte Carlo methods for light propagation in biological tissues
• Beer–Lambert law for optical tissue diagnostics: current state of the art and the main limitations
• Synthetic Wavelength Imaging -- Utilizing Spectral Correlations for High-Precision Time-of-Flight Sensing