Sung-Woong Shin

Wearable Respiratory Rate Monitoring using Piezo-resistive Fabric Sensor

The experimental results on respiratory rate monitoring using piezo-resistive fabric sensor under various moving environments are presented. As a basic biomedical signal for the healthcare monitoring, it is desirable to measure the respiratory rate even in the rapid running motion besides in the slow walking. We perform the experiment of respiratory rate monitoring using wearable piezo-resistive fabric sensor under various moving environments. In this paper, a preliminary measurement result is reported.

Magnetic particle imaging with a planar frequency mixing magnetic detection scanner

We present the first experimental results of our planar-Frequency Mixing Magnetic Detection (p-FMMD) technique to obtain Magnetic Particles Imaging (MPI). The p-FMMD scanner consists of two magnetic measurement heads with intermediate space for the analysis of the sample. The magnetic signal originates from the nonlinear magnetization characteristics of superparamagnetic particles as in case of the usual MPI scanner. However, the detection principle is different. Standard MPI records the higher order harmonic response of particles at a field-free point or line. By contrast, FMMD records a sum-frequency component generated from both a high and a low frequency magnetic field incident on the magnetically nonlinear particles. As compared to conventional MPI scanner, there is no limit on the lateral dimensions of the sample; just the sample height is limited to 2 mm. In addition, the technique does not require a strong magnetic field or gradient because of the mixing of the two different frequencies. In this study, we acquired an 18 mm × 18 mm image of a string sample decorated with 100 nm diameter magnetic particles, using the p-FMMD technique. The results showed that it is feasible to use this novel MPI scanner for biological analysis and medical diagnostic purposes.

In situ measurement of superoxide and hydroxyl radicals by frequency mixing detection technique

Frequency mixing magnetic detection (FMMD) was used to detect superoxide from hypoxanthine and xanthine reaction and to detect hydroxyl radical from the Fenton reaction. FMMD was also applied to measure the reactive oxygen species (ROS) level released from microglial cells. We could assess the formation and extinction of the free radicals without a spin trap reagent. The FMMD signal amplitude scaled with the concentration of the radicals. It was verified that no signals are obtained from the substrates and reagents. Based on the observations and on previous research, we suggest that the FMMD signals originate from superoxide and hydroxyl radicals, indicating that FMMD can be used to detect O-centered radicals. Subsequent analysis of free radicals generated from living microglial cells showed that there were significant differences between the activated microglial cells and resting ones. The results of this research are promising regarding the applications of FMMD for in situ measurement of free radicals from various sources, including the cell.

Magnetic immunoassay based on frequency mixing magnetic detection and magnetic particles of different magnetic properties

A novel analytical system is presented that employs two different types of magnetic particles (MPs) with frequency mixing magnetic detection (FMMD). A model experiment with MPs and FMMD demonstrates that this method significantly reduces the steps involved in common immunobiological assays and enables repetition of the measurement without signal decay.

True Ortho-photo Generation from High Resolution Satellite Imagery

Ortho-photos contain highly valuable data with high potential. They are useful in various applications, such as the creation of image maps and texture information in Geographic Information System (GIS). The Z-buffer method has been one of the most popular methods for the true ortho-photo generation. However, it has strict requirements regarding the Digital Surface Model (DSM) cell size. Furthermore, Z-buffer Method have false visibility problmes in narrow vertical structrues. The Z-buffer Method can be modified to avoid this problem using pseudo points along vertical surfaces. However, this method still has problems with certain DSM resolutions. This study implements two technical approaches for true ortho-photo generation u(l) the horizontal position of a point along the search path reaches the nadir point in the object space sing high resolution satellite imagery. The first approach deals with the scan line search method, which is required since each scan line has its own perspective center. The other approach is concerned with occlusion detection, which is required for the creation of true ortho-photos. Final experimental results with real data have demonstrated the feasibility of this proposed true ortho-photo generation methodology.

Frequency Mixing Magnetic Detection Scanner for Imaging Magnetic Particles in Planar Samples

The setup of a planar Frequency Mixing Magnetic Detection (p-FMMD) scanner for performing Magnetic Particles Imaging (MPI) of flat samples is presented. It consists of two magnetic measurement heads on both sides of the sample mounted on the legs of a u-shaped support. The sample is locally exposed to a magnetic excitation field consisting of two distinct frequencies, a stronger component at about 77 kHz and a weaker field at 61 Hz. The nonlinear magnetization characteristics of superparamagnetic particles give rise to the generation of intermodulation products. A selected sum-frequency component of the high and low frequency magnetic field incident on the magnetically nonlinear particles is recorded by a demodulation electronics. In contrast to a conventional MPI scanner, p-FMMD does not require the application of a strong magnetic field to the whole sample because mixing of the two frequencies occurs locally. Thus, the lateral dimensions of the sample are just limited by the scanning range and the supports. However, the sample height determines the spatial resolution. In the current setup it is limited to 2 mm. As examples, we present two 20 mm × 25 mm p-FMMD images acquired from samples with 1 µm diameter maghemite particles in silanol matrix and with 50 nm magnetite particles in aminosilane matrix. The results show that the novel MPI scanner can be applied for analysis of thin biological samples and for medical diagnostic purposes.

Development of the LiDAR data processing system for the rapid generation of the terrestrial information

This paper present an improved application system which can generate the 2.5D or 3D terrestrial information like DSM, DEM rapidly using LiDAR data. To process and manipulate input LiDAR data, various function modules are contained in the developed system. It allows users to display LIDAR data using TINS and even allows users to analyze the data using a profile viewer. In addition, the system also allows users to save the processed data with LAS file format, ASCII format.

A Development of Change Detection System for Urban Monitoring

This paper presents the application system of remote sensing which monitors urban objects. The system mainly aims to help public officials detect the changed areas using easy method and friendly user interface. The land cover images and the ortho-rectified aerial images which have been linked together by using geo-coordinates information are the main data to be imported and processed in the system. The modules in the system have consisted of land cover change detection and urban change detection. The latter one is for urban monitoring and planning, vector data update. Especially, urban change detection module is very useful to reduce workload of public officials performing aerial image interpretation. To be more specific, an image differencing technique and change vector technique in conjunction with transparency viewing function are employed to detect the candidates of changed area and object. Change vector technique is based on the concept of spectral angle difference of pixels in image space between co-registered images from two dates. A final product is an image layer indicating location where change occurred by overlaying of digital thematic map. We mainly present the procedure regarding change detection run by Link Viewer module.