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Full-Text Articles in Medicine and Health Sciences
Pilot Study Assessment Of Dynamic Vascular Changes In Breast Cancer With Near-Infrared Tomography From Prospectively Targeted Manipulations Of Inspired End-Tidal Partial Pressure Of Oxygen And Carbon Dioxide, Shudong Jiang, Brian W. Pogue, Kelly E. Michaelsen, Michael Jermyn, Michael A. Mastanduno, Tracy E. Frazee, Peter A. Kaufman, Keith D. Paulsen
Pilot Study Assessment Of Dynamic Vascular Changes In Breast Cancer With Near-Infrared Tomography From Prospectively Targeted Manipulations Of Inspired End-Tidal Partial Pressure Of Oxygen And Carbon Dioxide, Shudong Jiang, Brian W. Pogue, Kelly E. Michaelsen, Michael Jermyn, Michael A. Mastanduno, Tracy E. Frazee, Peter A. Kaufman, Keith D. Paulsen
Dartmouth Scholarship
The dynamic vascular changes in the breast resulting from manipulation of both inspired end-tidal partial pressure of oxygen and carbon dioxide were imaged using a 30 s per frame frequency-domain near-infrared spectral (NIRS) tomography system. By analyzing the images from five subjects with asymptomatic mammography under different inspired gas stimulation sequences, the mixture that maximized tissue vascular and oxygenation changes was established. These results indicate maximum changes in deoxy-hemoglobin, oxygen saturation, and total hemoglobin of 21, 9, and 3%, respectively. Using this inspired gas manipulation sequence, an individual case study of a subject with locally advanced breast cancer undergoing neoadjuvant …
Continuous Correction Of Differential Path Length Factor In Near-Infrared Spectroscopy, Tanveer Talukdar, Jason H. Moore, Solomon G. Diamond
Continuous Correction Of Differential Path Length Factor In Near-Infrared Spectroscopy, Tanveer Talukdar, Jason H. Moore, Solomon G. Diamond
Dartmouth Scholarship
In continuous-wave near-infrared spectroscopy (CW-NIRS), changes in the concentration of oxyhemoglobin and deoxyhemoglobin can be calculated by solving a set of linear equations from the modified Beer-Lambert Law. Cross-talk error in the calculated hemodynamics can arise from inaccurate knowledge of the wavelength-dependent differential path length factor (DPF). We apply the extended Kalman filter (EKF) with a dynamical systems model to calculate relative concentration changes in oxy- and deoxyhemoglobin while simultaneously estimating relative changes in DPF. Results from simulated and experimental CW-NIRS data are compared with results from a weighted least squares (WLSQ) method. The EKF method was found to effectively …
White Light-Informed Optical Properties Improve Ultrasound-Guided Fluorescence Tomography Of Photoactive Protoporphyrin Ix, Brendan P. Flynn, Alisha V. Dsouza, Stephen C. Kanick, Scott C. Davis, Brian W. Pogue
White Light-Informed Optical Properties Improve Ultrasound-Guided Fluorescence Tomography Of Photoactive Protoporphyrin Ix, Brendan P. Flynn, Alisha V. Dsouza, Stephen C. Kanick, Scott C. Davis, Brian W. Pogue
Dartmouth Scholarship
Subsurface fluorescence imaging is desirable for medical applications, including protoporphyrin-IX (PpIX)-based skin tumor diagnosis, surgical guidance, and dosimetry in photodynamic therapy. While tissue optical properties and heterogeneities make true subsurface fluorescence mapping an ill-posed problem, ultrasound-guided fluorescence-tomography (USFT) provides regional fluorescence mapping. Here USFT is implemented with spectroscopic decoupling of fluorescence signals (auto-fluorescence, PpIX, photoproducts), and white light spectroscopy-determined bulk optical properties. Segmented US images provide a priori spatial information for fluorescence reconstruction using region-based, diffuse FT. The method was tested in simulations, tissue homogeneous and inclusion phantoms, and an injected-inclusion animal model. Reconstructed fluorescence yield was linear with PpIX …
Compliant Head Probe For Positioning Electroencephalography Electrodes And Near-Infrared Spectroscopy Optodes, Paolo Giacometti, Solomon G. Diamond
Compliant Head Probe For Positioning Electroencephalography Electrodes And Near-Infrared Spectroscopy Optodes, Paolo Giacometti, Solomon G. Diamond
Dartmouth Scholarship
A noninvasive head probe that combines near-infrared spectroscopy (NIRS) and electroencephalography (EEG) for simultaneous measurement of neural dynamics and hemodynamics in the brain is presented. It is composed of a compliant expandable mechanism that accommodates a wide range of head size variation and an elastomeric web that maintains uniform sensor contact pressure on the scalp as the mechanism expands and contracts. The design is intended to help maximize optical and electrical coupling and to maintain stability during head movement. Positioning electrodes at the inion, nasion, central, and preauricular fiducial locations mechanically shapes the probe to place 64 NIRS optodes and …