Engineering Commons^™

Diffuse Optical Measurements Of Head And Neck Tumor Hemodynamics For Early Prediction Of Chemoradiation Therapy Outcomes, Lixin Dong, Mahesh Kudrimoti, Daniel Irwin, Li Chen, Sameera Kumar, Yu Shang, Chong Huang, Ellis L. Johnson, Scott D. Stevens, Brent J. Shelton, Guoqiang Yu

Biomedical Engineering Faculty Publications

This study used a hybrid near-infrared diffuse optical instrument to monitor tumor hemodynamic responses to chemoradiation therapy for early prediction of treatment outcomes in patients with head and neck cancer. Forty-seven patients were measured once per week to evaluate the hemodynamic status of clinically involved cervical lymph nodes as surrogates for the primary tumor response. Patients were classified into two groups: complete response (CR) (n = 29) and incomplete response (IR) (n = 18). Tumor hemodynamic responses were found to be associated with clinical outcomes (CR/IR), wherein the associations differed depending on human papillomavirus (HPV-16) status. In HPV-16 …

Low-Cost Compact Diffuse Speckle Contrast Flowmeter Using Small Laser Diode And Bare Charge-Coupled-Device, Chong Huang, Myeongsu Seong, Joshua Paul Morgan, Siavash Mazdeyasna, Jae Gwan Kim, Jeffrey Todd Hastings, Guoqiang Yu

Biomedical Engineering Faculty Publications

We report a low-cost compact diffuse speckle contrast flowmeter (DSCF) consisting of a small laser diode and a bare charge-coupled-device (CCD) chip, which can be used for contact measurements of blood flow variations in relatively deep tissues (up to ∼8  mm). Measurements of large flow variations by the contact DSCF probe are compared to a noncontact CCD-based diffuse speckle contrast spectroscopy and a standard contact diffuse correlation spectroscopy in tissue phantoms and a human forearm. Bland–Altman analysis shows no significant bias with good limits of agreement among these measurements: 96.5% ± 2.2% (94.4% to 100.0%) in phantom experiments and 92.8% …

Segway: A Simple Framework For Unsupervised Sleep Segmentation In Experimental Eeg Recordings, Farid Yaghouby, Sridhar Sunderam

Biomedical Engineering Faculty Publications

Sleep analysis in animal models typically involves recording an electroencephalogram (EEG) and electromyogram (EMG) and scoring vigilance state in brief epochs of data as Wake, REM (rapid eye movement sleep) or NREM (non-REM) either manually or using a computer algorithm. Computerized methods usually estimate features from each epoch like the spectral power associated with distinctive cortical rhythms and dissect the feature space into regions associated with different states by applying thresholds, or by using supervised/unsupervised statistical classifiers; but there are some factors to consider when using them:

• Most classifiers require scored sample data, elaborate heuristics or computational steps not easily …

Supernormal Conduction And Suppression Of Spatially Discordant Alternans Of Cardiac Action Potentials, Linyuan Jing, Anuj Agarwal, Abhijit R. Patwardhan

Biomedical Engineering Faculty Publications

Spatially discordant alternans (DA) of action potential durations (APD) is thought to be more pro-arrhythmic than concordant alternans. Super normal conduction (SNC) has been reported to suppress formation of DA. An increase in conduction velocity (CV) as activation rate increases, i.e., a negative CV restitution, is widely considered as hallmark of SNC. Our aim in this study is to show that it is not an increase in CV for faster rates that prevents formation of DA, rather, it is the ratio of the CV for the short relative to the long activation that is critical in DA suppression. To illustrate …

Recent Advances In Optical Spectroscopic And Imaging Methods For Medicine And Biology, Yu Shang, Zhiyu Qian, Rickson C. Mesquita, Mathieu Dehaes

Biomedical Engineering Faculty Publications

No abstract provided.