The Association between Symptoms of Autonomic Neuropathy and the Heart Rate Variability in Diabetics / 가정의학회지

BACKGROUND: There are few tools to detect the diabetic autonomic neuropathy at an earlier stage. This study was conducted to investigate the association between symptoms of autonomic neuropathy and the heart rate variability (HRV) in diabetics. METHODS: Study subjects consisted of 50 diabetic patients and 30 outpatient hospital control patients at a university family medicine department. The patients completed a Korean version of composite autonomic symptom scale (COMPASS). Electrocardiography was recorded in the supine position, on standing, and during deep breathing, for 5 minutes each. HRV of frequency domain was calculated by power spectral analysis. RESULTS: The COMPASS score was higher in female diabetic patients compared with that in controls. Among 50 diabetic patients, the total COMPASS score correlated positively with normalized low frequency (LF) score (normalized units, n.u.) (r = 0.62, P < 0 .001) and low frequency/high frequency (LF/HF) (r = 0.77, P < 0.001), negatively with normalized HF score (n.u.) (r = -0.59, P < 0.001) and RMSSD (square root of the mean of the sum of the square of differences between adjacent NN interval; r = -0.33, P = 0.031). The decrease in LF (n.u) and the increase in HF (n.u) by deep breathing from the supine position were higher in diabetic patients compared with those in controls. The increase in LF (n.u) and the decrease in HF (n.u) by standing from the supine position were lower in diabetic patients compared with those in controls. CONCLUSION: The COMPASS score correlated with some component score of the HRV in diabetics. The HRV may be used as a tool to detect diabetic autonomic neuropathy by augmentation with position change.

Hierarchical Classification of ECG Beat Using Higher Order Statistics and Hermite Model / 대한의료정보학회지

OBJECTIVE: The heartbeat classification of the electrocardiogram is important in cardiac disease diagnosis. For detecting QRS complex, conventional detection algorithmhave been designed to detect P, QRS, Twave, first. However, the detection of the P and T wave is difficult because their amplitudes are relatively low, and occasionally they are included in noise. Furthermore the conventionalmulticlass classificationmethodmay have skewed results to themajority class, because of unbalanced data distribution. METHODS: The Hermite model of the higher order statistics is good characterization methods for recognizing morphological QRS complex. We applied three morphological feature extraction methods for detecting QRS complex: higher-order statistics, Hermite basis functions andHermitemodel of the higher order statistics.Hierarchical scheme tackle the unbalanced data distribution problem. We also employed a hierarchical classification method using support vector machines. RESULTS:We compared classification methods with feature extraction methods. As a result, our mean values of sensitivity for hierarchical classification method (75.47%, 76.16% and 81.21%) give better performance than the conventionalmulticlass classificationmethod (46.16%). In addition, theHermitemodel of the higher order statistics gave the best results compared to the higher order statistics and the Hermite basis functions in the hierarchical classification method. CONCLUSION: This research suggests that the Hermite model of the higher order statistics is feasible for heartbeat feature extraction. The hierarchical classification is also feasible for heartbeat classification tasks that have the unbalanced data distribution.

Newly developing endoscopic devices--shadow optics and micromachine

Based on the newly-developed engineering technologies, many kinds of useful equipment have been available for minimally invasive surgery. Recently the time to connect clinical needs and advanced technologies has become faster. In this article, we have summarized the recent technologies for endoscopic surgeries. Shadow optic technologies for better geometric perception using dual illumination in a conventional 2-D monitor and "Overview optics" for a panoramic view with an additional visual system are introduced. Micromachine technology is very close to practical implementation for minimally invasive surgeries. Virtual Biopsy is the one of the hottest topics for the next generation of endoscopy. Stereoscopic and volumetric vision systems are still on the way, which should overcome the irritating goggles and stereo display devices. As well as operational theater that integrates all the required equipment with a computer-based system, including voice recognition, still requires the standard protocols to connect many kinds of devices from different manufacturers.

Development of Home Health Monitoring System using Digital Telemetry / 대한의료정보학회지

We developed the system that enables patients to be treated at home during their daily life through digital telemetry and public communication line. In this study, video conference based remote examination and wireless telemetry were integrated together to form a remote monitoring homecare system, and underwent the validation. Test ECG signals were transmitted wirelessly unhindering the person's movement in one floor of our building, and the stability was assessed. The signal were transmitted to remote host via ISDN, with the patient's voice and moving image. To control the system and manage files remotely, the interactive model was devised for this study.