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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
> Journal Vol & Issue
Journal of Biomedical Engineering Research
Journal Basic Information
Journal DOI :
The Korea Society of Medical and Biological Engineering
Editor in Chief :
Volume & Issues
Volume 29, Issue 6 - Dec 2008
Volume 29, Issue 5 - Oct 2008
Volume 29, Issue 4 - Aug 2008
Volume 29, Issue 3 - Jun 2008
Volume 29, Issue 2 - Apr 2008
Volume 29, Issue 1 - Feb 2008
Selecting the target year
Electrochemical Biosensors for U-Healthcare
Kim, Sang-Kyu ; Chung, Bong-Hyun ;
Journal of Biomedical Engineering Research, volume 29, issue 5, 2008, Pages 337~342
To date, many researchers have developed a variety of biosensors to detect the biomolecular interactions. Recently, electrochemical biosensors have been attracting great interest as one of key technologies in a ubiquitous healthcare (U-healthcare) system since they are highly sensitive and feasible to miniaturize. Here we overview the current electrochemical biosensors based on strip-type, nanowire/nanotube, field effect transistor (FET), and nanogap electrode.
Thermal Property Measurement of Swine Atrium
Oh, Jung-Hwan ; Kim, Jee-Hyun ;
Journal of Biomedical Engineering Research, volume 29, issue 5, 2008, Pages 343~347
Thermal conductivity, thermal diffusivity were measured in the atrium of a swine heart. Radiofrequency (RF) catheter ablation in an atrium has rapidly emerged at the treatment of symptomatic reentrant arrhythmia associated with accessory pathway or Atrioventricular (AV) node conduction. The thermal properties of an atrium are definitely necessary for these treatments because, in thermal treatments, conductivity and diffusivity are significant factors in the relationship between the applied RF power and the resulting atrium temperature rise. Thermal properties were measured using a self-heated thermistor probe. Thermistor probes were inserted into the tissue of interest and were used to supply heat within the tissue as well as to monitor the temperature rise in the tissue. The measurements were performed at temperatures of 25, 37,
. Atrium thermal conductivity ranged from 5.17
. Atrium thermal diffusivity ranged from 0.00132
. This paper also present the thermal property comparison of both chambers of a heart (ventricle and atria).
A Fast Lower Extremity Vessel Segmentation Method for Large CT Data Sets Using 3-Dimensional Seeded Region Growing and Branch Classification
Kim, Dong-Sung ;
Journal of Biomedical Engineering Research, volume 29, issue 5, 2008, Pages 348~354
Segmenting vessels in lower extremity CT images is very difficult because of gray level variation, connection to bones, and their small sizes. Instead of segmenting vessels, we propose an approach that segments bones and subtracts them from the original CT images. The subtracted images can contain not only connected vessel structures but also isolated vessels, which are very difficult to detect using conventional vessel segmentation methods. The proposed method initially grows a 3-dimensional (3D) volume with a seeded region growing (SRG) using an adaptive threshold and then detects junctions and forked branches. The forked branches are classified into either bone branches or vessel branches based on appearance, shape, size change, and moving velocity of the branch. The final volume is re-grown by collecting connected bone branches. The algorithm has produced promising results for segmenting bone structures in several tens of vessel-enhanced CT image data sets of lower extremities.
Constrained Independent Component Analysis Based Extraction and Mapping of the Brain Alpha Activity in EEG
Ahn, S.H. ; Rasheed, T. ; Lee, W.H. ; Kim, T.S. ; Cho, M.H. ; Lee, S.Y.. ;
Journal of Biomedical Engineering Research, volume 29, issue 5, 2008, Pages 355~363
In order to extract only the alpha activity related signals from EEG recordings, we have applied Constrained Independent Component Analysis (cICA), a new extension of ICA in which some a priori knowledge of the alpha activity is utilized to extract only desired components. Its extraction (or filtering) performance has been compared to that of the conventional band-pass filtering via the scalp alpha power maps and cortical source maps of the alpha activity. Our results demonstrate that the alpha power maps and cortical source maps from the cICA-extracted alpha signals reveal more focalized alpha generating regions of the brain than those from the band-pass filtered alpha EEG signals. Furthermore they match more closely the activated regions of the brain mapped using fMRI, validating our results. We believe that the cICA-based filtering approach of EEG signals is a more effective means of extracting a specific brain activity reflected in EEG signals that will result in more accurate source localization or imaging maps.
Digital Tomosynthesis using a Flat-panel Detector based Micro-CT
Mandai, Koushik Kanti ; Choi, Jeong-Min ; Cho, Min-Hyoung ; Lee, Soo-Yeol ;
Journal of Biomedical Engineering Research, volume 29, issue 5, 2008, Pages 364~370
Recent development in large area flat-panel x-ray detector technology enables clinical application of digital tomosyntesis. Unlike conventional motion tomography using x-ray films, flat-panel x-ray detectors provide projection images in digital formats so that tomographic images can be synthesized in a more flexible way. For the digital tomosynthesis, precise movements of the x-ray source and the x-ray detector with respect to a fulcrum point are necessary. In this study, we apply the digital tomosynthesis technique to the flat-panel detector based micro-CT in which the flat-panel detector and the x-ray source rotate together on a circular arc. The experimental results suggest that flat-panel detector based 3D CTs can be used for digital tomosynthesis in the clinical environment.
Estimation of Target and Completion Pressure during the Cuff Inflation Phase in Blood Pressure Measurement
Oh, Hong-Sic ; Lee, Jong-Shill ; Kim, Young-Soo ; Shen, Dong-Fan ; Kim, In-Young ; Chee, Young-Joan ;
Journal of Biomedical Engineering Research, volume 29, issue 5, 2008, Pages 371~375
In blood pressure measurement, the oscillometric method detects and analyzes the pulse pressure oscillation while deflating the cuff around the arm. For its principle, one has to inflate cuff pressure above the subject's systolic pressure and deflate below the diastolic pressure. Most of the commercialized devices inflate until the fixed target pressure and deflate until the fixed completion pressure because there is no way to know the systolic and diastolic pressure before measurement. Too high target pressure makes stress to the subject and too low target pressure makes big error or long measurement time because of re-inflation. There are similar problems for inadequate completion pressure. In this study, we suggest new algorithm to set proper target and completion pressure for each subject by analyzing pressure waveform while inflating period. We compared our proposed method and auscultation method to see the errors of estimation. The differences between the two measurements were -4.02
10.57mmHg and -0.78
5.l7mmHg for mean arterial pressure, systolic pressure and diastolic pressure respectively. Consequently, we could set the target pressure by 30 mmHg higher than our estimation and we could stop at 20mmHg lower than our estimated diastolic pressure. Using this method, we could reduce the measurement time.
Improvement of Convection by Pulsatile Blood Pump in High Flux Hemodialysis System
Choi, D.S. ; Um, K.M. ; Lee, J.C. ; Lee, S.R. ; Mun, C.H. ; Choi, H. ; Min, B.G. ; Kim, H.C. ;
Journal of Biomedical Engineering Research, volume 29, issue 5, 2008, Pages 376~383
High-flux dialysis treatment removes various toxins via diffusion as well as convection, which is induced by ultrafiltration and backfiltration. In this study, in vitro (Using the distilled water and the bovine's blood) comparison test was performed to determine whether utilization of a high flux dialyzer paired with different pumps would increase the efficiency of convection. At the same blood flow rates, a pulsatile pump and a roller pump were employed to propel the distilled water and bovine whole blood to a high flux dialyzer. Pressures at the dialyzer inlet and outlet in the blood circuit and in the dialysate circuit were measured, respectively. From these data, we calculated the transmembrane pressure and predicted the ultrafiltration and backfiltration rates developed by both pumps. Using the bovine's blood experiment, ultrafiltration and backfiltration rates were 1.6 times higher with the pulsatile pump than with the roller pump. We conclude that utilization of a pulsatile pump in high flux hemodialysis treatments increases ultrafiltration volume, compared with a roller pump under conditions of the same blood flow rate.
Object Search Using Synchronous Ultrasonic Wave Emission for the Blind Guide system
Kim, Chang-Geol ; Song, Byung-Seop ;
Journal of Biomedical Engineering Research, volume 29, issue 5, 2008, Pages 384~391
For use in the guide system for the people who are visually impaired, an obstacle searching device using synchronous ultrasonic wave emission was proposed and developed. Generally, the conventional obstacle detection methods use the ultrasonic distance measuring device with successive scan method. However, the scan method causes a theoretical error and it couldn't estimate accurate obstacle distances. The proposed synchronous firing method use the plural number of ultrasonic sensors which emit ultrasonic wave simultaneously and estimate the distance to the closest obstacle relatively accurately. We analytically analyzed the errors of the conventional and proposed methods and compared the quantitative differences of the errors. The differences verified by obstacle search experiments. Using the proposed ultrasonic wave synchronous firing method, 3 dimensional obstacle location estimating device was designed and implemented. The results of the 3 dimensional obstacle detecting experiments showed the proposed method had good performances and it would be sufficiently use in the guide system for the people who are visually impaired.
Optimal Design of a-Si TFT Array for Minimization of Data-line Capacitance and Its Implementation
Kim, C.W. ; Yoon, J.K. ; Kim, S.Y. ; Kim, J.H. ;
Journal of Biomedical Engineering Research, volume 29, issue 5, 2008, Pages 392~399
Thin-film transistor (TFT) arrays for an x-ray detector require quite different design concept from that of the conventional active-matrix liquid crystal devices (AM-LCDs). In this paper anew design of TFT array which uses only SiNx for passivation layer is described to meet the detector performance and the product availability simultaneously. For the purpose of optimizing the design parameters of the TFT array, a Spice simulation was performed. As a result, some parameters, such as the TFT width, the data line capacitance, and the storage capacitance, were able to be fixed. The other parameters were decided within a permissible range of the TFT process especially the photolithography process and the wet etch process. Then we adapted the TFT array which had been produced by the proposed design to our prototype model (FDXD-1417 and evaluated it clinically by comparing with a commercial model (EPEX, Hologic, Beford, USA). The results say that our prototype model is slightly better than EPEX system in chest PA images. So we can prove the technical usefulness and the commercial values of the proposed TFT design.
A Suggestion on Evaluating Personal Health State: Health Index
Moon, Dong-Ju ; Lee, Sung-Il ; Lee, Chong-Sun ; Kim, Gyeong-Cheol ; Kang, Hee-Jung ; Yang, Yong-Ju ;
Journal of Biomedical Engineering Research, volume 29, issue 5, 2008, Pages 400~407
A health index was proposed that evaluates personal health state from both measured physiological variables and survey questions. Four health indices were defined such as cardiovascular index, stress index, obesity index, and management index. The total health index was calculated by summing these four health indices. Physiological variables such as blood pressure, heart rate variability(HRV), accelerated photoplethysmograph(APG), and body fat percentage were non-invasively measured and a survey questionnaire that asks personal health state, exercise intensity, and food preference was developed. The suggested health index was applied to thirty eight persons including 30 patients and 8 normal persons with an average age of 51.8. The average health index was estimated to be 75.1 out of 100 points. Young age group(below 50) and men group showed higher health indices than the aged(over 50) and women groups. The correlation coefficient between the cardiovascular index and stress index was found to be 0.513, which means stress is related to cardiovascular health state. The correlation coefficient between the measurements and survey questions was 0.385 for the cardiovascular index. It was as low as 0.182 for the stress index. More case studies may improve correlations between measurements and survey questions, and then, the current health index system may develop as an effective tool to evaluate personal health state.
Response Properties of Acupuncture Stimulation by Meridian Electrical Potential Measurement
Ryu, Yeon-Hang ; Jung, Byung-Jo ; Lee, Yong-Heum ;
Journal of Biomedical Engineering Research, volume 29, issue 5, 2008, Pages 408~413
Human body has a complete left and right symmetry structure, and the left and right balance by Yin and Yang. When the balance is broken, the left and right Meridian becomes abnormal condition. Acupuncture is a kind of therapy to recover from energy unbalance of the left and right Meridian to a new balance condition. In the study, we observed the electric potential along the stomach meridian (ST) in order to verify the energy consensus phenomenon by transportation of bio-energy between operator and subject during acupuncture. The acupuncture effects on opposite meridian site were investigated by comparing the electric potentials between the right and left ST sites. Meridian electrical potentials (MEPs) between operator and subject were simultaneously generated during the acupuncture and the polarity of MEPs was opposite. The results might imply the bio-energy transportation between operator and subject. In addition, we observed three different patterns of MEPs on both ST sites which might represent the condition of the related meridians because meridians in the body are organically interconnected.