Simple camera calibration for light measurements
The availability and decreasing prices of digital photographic cameras using megapixel sensors could point to its use as high quality light measuring devices if simple and effective calibration procedures could be put to work. This paper proposes such a system, using a common digital camera combined with low cost reference color charts. The procedure to obtain the response function of the camera, the production of the color chart and its calibration is presented. In this way, it is possible to obtain light measurements otherwise only possible with sophisticated and expensive equipments.
Estimation of Neonatal Jaundice from the Chest Images Captured with a Smartphone
Hyperbilirubinemia is a common problem in neonatal for contact with the healthcare facilities. Several methods have been used to determine the bilirubin concentration. However, it is not easy to find the healthcare with the instrument to detect bilirubin, mainly in rural area. This research was aimed to develop a simple method for neonatal hyperbilirubinemia based on the chest images captured using a smartphone. A total of 31 randomly selected neonatal were studied, with the parental inform consent. The chest images have been capture using smartphone camera with the standard color chart besides the neonatal. The captured images were then analyzed by extracting the color intensity using ImageJ software. The bilirubin concentration obtained using standard method from the hospital were then analyzed to show the association of the chest color intensity with the bilirubin concentration. The result showed a high correlation between the blue color intensity and the blood bilirubin with the regression line of y = -0.466x + 162.84 (R = 0.851). The result of this study indicated the smartphone camera images of neonatal chest could be used for a simple screening tool of neonatal hyperbilirubinemia. Further study could be performed for smartphone software development of the bilirubin prediction from the neonatal chest images.
Microwave source with enhanced radiation power based on orbitron MASERs
We have proposed the design of high power microwave source in a vacuum tube based on the theory of negative mass instability. The proposed source does not operate based on a slow-wave structure but instead makes use of accelerated charged particles. In our structure, an electron emitter injects the charged particles into to the cavity. Emitted particles move around the anode, which leads to electron acceleration and emission of electromagnetic waves with a specific frequency. In this paper, we have enhanced the output power and frequency of microwave source by variation of particles initial energy and the number of anodes incorporating their specific arrangement and applied voltages. Working at room temperature, compactness, wide bandwidth, and tunability of output frequency are among the advantages of the proposed source.