ABSTRACT
BACKGROUND AND OBJECTIVE: Tissue blood oxygenation contains critical information for biomedical studies and healthcare. The primary approach to extract the absolute value of tissue blood oxygenation (e.g., oxygen saturation) is spatial-resolved algorithm for near-infrared diffuse optical spectroscopy with continues-wave (CW) light, which require acquisition of the optical signals from multiple pairs of sources and detectors (S-D). This study reports the first attempt for absolute oxygenation measurement with single S-D pair of optical signals. METHODS: A novel algorithm, namely, phantom-validation modified Beer-Lambert law (PV-MBLL), was created to fully utilize the optical signals from single S-D pair. This algorithm is combined with two-step phantom measurement to extract the absolute value of tissue oxygenation in CW system. The proposed PV-MBLL algorithm was compared with the conventional spatial-resolved algorithm on both step-varied liquid phantom and human experiment of cuff occlusion on arms. The one-way ANOVA analysis was performed to investigate the difference between the two algorithms. RESULTS: By using the PV-MBLL algorithm, the reconstructed tissue absorption coefficient is highly accurate (not larger than 5.35% in error) over a wide range (0.02-0.20 cm-1). By contrast, the spatial-resolved algorithm leads to much larger errors (up to 37.57% in error). Moreover, the responses of oxygen saturation to cuff occlusion differ significantly (p < 0.005) with the two algorithms. CONCLUSIONS: The proposed PV-MBLL algorithm has promising potential for accurate acquisition of oxygenation information. Additionally, the single S-D pair greatly reduces the size of optical probe and instrument cost, thus it is highly appropriate for the tissues with small size and large curvature.
Subject(s)
Algorithms , Spectroscopy, Near-Infrared , Humans , Phantoms, ImagingABSTRACT
Tissue hemodynamics, including the blood flow, oxygenation, and oxygen metabolism, are closely associated with many diseases. As one of the portable optical technologies to explore human physiology and assist in healthcare, near-infrared diffuse optical spectroscopy (NIRS) for tissue oxygenation measurement has been developed for four decades. In recent years, a dynamic NIRS technology, namely, diffuse correlation spectroscopy (DCS), has been emerging as a portable tool for tissue blood flow measurement. In this article, we briefly describe the basic principle and algorithms for static NIRS and dynamic NIRS (i.e., DCS). Then, we elaborate on the NIRS instrumentation, either commercially available or custom-made, as well as their applications to physiological studies and clinic. The extension of NIRS/DCS from spectroscopy to imaging was depicted, followed by introductions of advanced algorithms that were recently proposed. The future prospective of the NIRS/DCS and their feasibilities for routine utilization in hospital is finally discussed.
Subject(s)
Hemodynamics/physiology , Spectroscopy, Near-Infrared , Algorithms , Animals , Humans , Mice , Oxygen/blood , Rats , Spectroscopy, Near-Infrared/instrumentation , Spectroscopy, Near-Infrared/methodsABSTRACT
In the crystal structure of the title compound, C(10)H(8)BrN(3)O, the dihedral angle between the two pyridine rings is 2.48â (2)°. A weak intramolecular N-Hâ¯O hydrogen bond is present.
ABSTRACT
OBJECTIVE: To explore an early stage repair method for soft tissue defect of limbs of modern firearm wound, and to improve treating result. METHODS: Defects of the hind limbs of dogs were repaired with skin, muscle and myocutaneous flaps. RESULTS: Wounds healed within 2 weeks in the experimental group except one that healed in 3 weeks because of infection. Limb function was close to normal. The treatment result was better in the experimental group than the control. CONCLUSIONS: Skin, muscle and myocutaneous flaps can cover soft tissue defect at an early stage, prevent and reduce infection, promote the healing and recovery of combined injury, reduce the time of treatment and disability rate.