Fast and accurate energy calibration of photon counting spectral detectors (PCSDs) is essential for their biomedical applications to identify and characterize bio-components or contrast agents in tissues. Using the x-ray tube voltage as a reference for energy calibration is known to be an efficient method, but there has been no consideration in the energy calibration of non-convergent behavior of PCSDs. We observed that a single pixel mode (SPM) CdTe PCSD based on Medipix-2 shows some non-convergent behaviors in turning off the detector elements when a high enough threshold is applied to the comparator that produces a binary photon count pulse.
View Article and Find Full Text PDFIn traditional Chinese and Korean medicine, doctors first observe a patient's pulse by gently and strongly pressing their fingers onto the wrist, and then make a diagnosis based on the observed pulse waves. The most common method to implement this diagnostic technique is to mechanically extract the pulse waves by applying a fixed range of pressures for all patients. However, this method does not consider the patients individual characteristics such as age, sex, and skin thickness.
View Article and Find Full Text PDFSeveral RPT sensors have been developed to acquire objective and quantitative pulse waves. These sensors offer improved performance with respect to pressure calibration, size and sensor deployment, but not temperature. Since most pressure sensors are sensitive to temperature, various temperature compensation techniques have been developed, but these techniques are largely inapplicable to RPT sensors due to the size restrictions of the sensor, and incompatibility between the compensation techniques and the RPT sensor.
View Article and Find Full Text PDFBiomed Eng Online
August 2012
Background: In sparse-view CT imaging, strong streak artifacts may appear around bony structures and they often compromise the image readability. Compressed sensing (CS) or total variation (TV) minimization-based image reconstruction method has reduced the streak artifacts to a great extent, but, sparse-view CT imaging still suffers from residual streak artifacts. We introduce a new bone-induced streak artifact reduction method in the CS-based image reconstruction.
View Article and Find Full Text PDFAnnu Int Conf IEEE Eng Med Biol Soc
July 2012
Pulse diagnosis, which is one of methods of diagnosis, is an important factor in oriental medicine. However, a problem in diagnosis with the pulse is that there is no objective standard. Therefore, the practitioners pass on the skill and students learn about pulse diagnosis as a method that depends on speech.
View Article and Find Full Text PDFIn this work a new spectrofluorimetric method for the determination of vitamin B(1), based on the catalytic activity of horseradish peroxidase (HRP) in the presence of hydrogen peroxide (H2O2), has been developed. Non-fluorescent vitamin B(1) was easily converted through catalytic oxidation in alkaline medium into a fluorescent compound, even without exposure to light. The linear range for vitamin B(1) observed was 0.
View Article and Find Full Text PDFA sensitive, rapid, and specific assay has been developed for the simultaneous determination of acetylsalicylic acid and caffeine in commercial tablets based on their natural fluorescence. The mixture of these drugs was resolved by first derivative synchronous fluorimetric technique using two scans. At Deltalambda=106 nm, using first derivative synchronous scanning, only acetylsalicylic acid yields a detectable signal at 316 nm (peak to zero method) which is unaffected by caffeine.
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