A combined diffuse speckle contrast analysis (DSCA)–near-infrared spectroscopy (NIRS) system is proposed to simultaneously measure qualitative blood flow and blood oxygenation changes in human tissue. The system employs an optical switch to alternate two laser sources at two different wavelengths and a CCD camera to capture the speckle image. Therefore, an optical density can be measured from two wavelengths for NIRS measurements and a speckle contrast can be calculated for DSCA measurements. In order to validate the system, a flow phantom test and an arm occlusion protocol for arterial and venous occlusion were performed. Shorter exposure times show a higher drop (between 50% and 66%) and recovery of 1/KS2 values after occlusion (approximately 150%), but longer exposure time (3 ms) shows more consistent hemodynamic changes. For four subjects, the 1/KS2 values dropped to an average of 82.1±4.0% during the occlusion period and the average recovery of 1/KS2 values after occlusion was 109.1±0.8%. There was also an approximately equivalent amplitude change in oxyhemoglobin (OHb) and deoxyhemoglobin (RHb) during arterial occlusion (max RHb=0.0085±0.0024 mM/DPF, min OHb=−0.0057±0.0044 mM/DPF). The sensitivity of the system makes it a suitable modality to observe qualitative hemodynamic trends during induced physiological changes.
A combined DSCA/NIRS system to measure blood flow and oxygenation simultaneously (Myeongsu Seong, Zeph Phillips, and Phuong Minh Mai)
创建: May 24, 2017 | 01:27
Optical Coherence Tomography (OCT) is an optical imaging technique based on low-coherent interferometry which employs near-infrared light to capture micrometer-scale, 3D optical scattering media. In our lab, we apply OCT to visualize the tumor blood vessel response during chemotherapy using a dorsal skin-fold window chamber model.
Blood vessel in nude mouse ear and dorsal window chamber (Hoonsup Kim et al.)
Tumor blood vessel in the window chamber before chemotherapy (Hoonsup Kim et al.)
Tumor blood vessel in the window chamber after chemotherapy (Hoonsup Kim et al.)
Link
创建: May 24, 2017 | 01:26
Cupping therapy is a form of oriental medicine that creates a local suction on the skin. The local suction mobilizes blood flow in the area and helps promote healing. However, conventional cupping therapy applied same force to everyone without considering about physical conditions such as age, sex, or weight. In order to make a personalized cupping therapy, we added a NIRS channel inside of the cup as an optical sensor to measure blood oxygenation during cupping.
Optical sensor for personalized cupping therapy (Sungchul Kim and Evgenii Kim)
创建: May 24, 2017 | 01:26
Near infrared spectroscopy (NIRS) is a non-invasive method which can detect the change of oxy- and deoxy-hemoglobin concentration using near infrared. In our lab, NIRS was applied to breast cancer study to predict chemotherapy efficacy early.
NIRS system for breast cancer study and oxy-, deoxy-hemoglobin, and tumor volume before and after chemotherapy (Songhyun Lee and Hyeryun Jeong)
In addition, NIRS was applied to sexual dysfunction study. NIRS was used to observe a discrepancy of penile hemodynamics during visual sexual stimulation.
NIRS signal was monitored from prefrontal lobe and genital organ during visual sexual stimulation (Evgenii Kim and Songhyun Lee)
创建: May 24, 2017 | 01:29
Currently, EEG and NIRS are common techniques to investigate brain functional activities due to their low cost, high temporal resolution, and portability. EEG provides brain activity information directly through electrical signal, while NIRS measures brain activity indirectly through hemodynamic response. In our lab, in order to complement information on hemodynamic responses of NIRS to EEG, we utilized a combined EEG/NIRS system to monitor anesthesia depth.
EEG electrode and NIRS optodes were surgically inserted to rat's brain to monitor anesthesia depth (Dong-Hyuk Choi, Seonghyun Kim, and Jaeyoung Bae)
In addition, combined EEG/NIRS system was noninvasively applied to human to detect driver drowsiness.
Combined EEG/NIRS in driver drowsiness detection study (Thien Nguyen et al.)
创建: May 24, 2017 | 01:30
We use multi-spectral images to acquire the melanin distribution and nevus information.
创建: May 24, 2017 | 01:31
