• Journal of Biomedical Engineering Research
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• v.20 no.1
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• pp.75-80
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• 1999

Since a Holter monitor records a patients' ECG when he is in motion, it can monitor complex heart disease effectively. But it can not handle a sudden heart disease because the diagnosis process will be done only after 24 hours. So in this study, a model of ambulatory monitoring system using wireless data communication network is proposed. And a mobile ECG equipment and a doctors' terminal are developed for the proposed system implementation. As a result, we can evaluate that the proposed ambulatory monitoring system is suitable for the management of ambulatory patients who may be at risk form sudden cardiac abnormalities.

• Proceedings of the KOSOMBE Conference
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• v.1997 no.05
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• pp.330-333
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• 1997

In this paper, we designed a low power and small-sized, light weighted intelligent ambulatory monitoring system using a flash memory card. The system's hardware specifications are as follows: 2 channels, 8bit/250Hz sampling rate, 20M byte storage capacity, a single-chip microcontroller (68HC11E9). To easily interface with PC based system, FFS(Flash File System) was used. We obtained the QRS detection rate of 99.14 through the evaluation with MIT/BIH database.

• Journal of Biomedical Engineering Research
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• v.12 no.4
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• pp.277-284
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• 1991

This study describes the ambulatory ECG monitoring system for the remote autom atic diagnosis. System: tlardware is based on one chip microcomputer(80c31) and its peripherals which consists of A/D, EPROM, RAM, LCD display and two preamplifiers, Power circuits, control logic circuits. A/D converted data were differentiated and low pass filtered. The detection of QRS complex and R point were accomplished by software algorithm based on adaptive threshold computed on low pass fi:leered signal. Rhythm analysis is performed by RR interval and average RR interval. The performance of QRS detection algorithm is evaluated by using MIT/BIH data base. Using this system, the trends of the arrythmia during the long term could be saved and displayed.

• Proceedings of the KIEE Conference
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• 2003.11c
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• pp.920-923
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• 2003

An wearable electrocardiogram (ECG) monitoring system is a widely used non-invasive diagnostic tool for ambulatory patient who may be at risk from latent life-threatening cardiac abnormalities. In this paper, we have a portable ECG monitoring system with conductive fiber which was characterized by the small-size and the low power consumption. The system consists of conductive fibers, one-chip microcontroller, ECG preprocessing circuit, and monitoring software to be able to record and analyze in PC. ECG preprocessing circuit is made of pre-amplifier with gain of 10, band-pass filter with bandwidth of 0.5-120Hz and 2.5V offset circuit for A/D conversion. ECG signals obtained by sensor are included with corrupted noises such as a baseline wandering, 60 Hz power noise and interference noise by body movement. For cancellation corrupted noises in signals obtained by conductive fiber, we used the wavelet decomposition of wavelet transforms in MATLAB toolbox.

• Proceedings of the KIEE Conference
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• 2005.05a
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• pp.48-50
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• 2005

Urodynamics describes a collection of tests designed to evaluate lower urinary tract function and can be performed using retrograde filling of the bladder within a room. In this study, we designed and calibrated the potable urodynamics monitoring system using DSP chip (TMS320VC33, Texas Instrument$^{TM}$, U.S.) and collected pressure and EMG using calibration kit (DPT9022K0122, Medtronics$^{TM}$, U.S.). This system can make patients more comportable and monitor spontaneous urination during daily life.

• Health Policy and Management
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• v.13 no.1
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• pp.98-115
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• 2003

Concerns about growing health insurance expenditures became a national Issue in 2001 when the National Health Insurance went into a deficit. Increases in spending for ambulatory care shared the largest portion of the problem. Methods and systems to control the spending should be developed and a system to measure case mix of providers is one of core components of the control system. The objectives of this article is to examine the feasibility of applying Korean Diagnosis Related Groups (KDRGs) to classify health insurance claims for ambulatory care and to identify problem areas of the classification. A database of 11,586,270 claims for ambulatory care delivered during January 2002 was obtained for the study, and the final number of claims analyzed was 8,319,494 after KDRG numbers were assigned to the data and records with an error KDRG were excluded from the study. The unit of analysis was a claim and resource use was measured by the sum of charges incurred during a month at a department of a hospital of at a clinic. Within group variance was assessed by th coefficient of variation (CV), and the classification accuracy was evaluated by the variance reduction achieved by the KDRG classification. The analyses were performed on both all and non-outlier data, and on a subset of the database to examine the validity of study results. Data were assigned to 787 KDRGs among 1,244 KDRGs defined in the classification system. For non-outlier data, 77.4％ of KDRGs had a CV of charges from tertiary care hospitals less than 100％ and 95.43％ of KDRGs for data from clinics. The variance reduction achieved by the KDRG classification was 40.80％ for non-outlier claims from tertiary care hospitals, 51.98％ for general hospitals, 40.89% for hospitals, and 54.99% for clinics. Similar results were obtained from the analyses performed on a subset of the study database. The study results indicated that KDRGs developed for a classification of inpatient care could be used for ambulatory care, although there were areas where the classification should be refined. Its power to predict tile resource utilization showed a potential for its application to measure case mix of providers for monitoring and managing delivery of ambulatory care. The issue concerning the quality of diagnostic information contained in insurance claims remains to be improved, and significance of future studies for other classification systems based on visits or episodes is guaranteed.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.56 no.6
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• pp.1170-1176
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• 2007

The conventional urodynamic monitoring is fulfilled by artificially filling a bladder with saline. Generally. it is difficult to evaluate the physiological functions of the storage and voiding of a bladder. With this aim, we constructed an ambulatory urodynamic monitoring (AUM) system and proposed a novel method estimating abdominal pressure by measuring bio-impedance variations. Our system was clinically evaluated for 10 patients. It turned out to be that as the intensity of the abdomen contraction increased, the amplitude of bio-impedance signal and the RMS value of EMG increased more as compared to those who observed during the rest mode. Also, we determined the optimum electrode pair for estimating the abdominal pressure using bio-impedance method and consequently compared with the conventional methods. Because impedance changes differ from a weight, a height, contractile force, volume of muscle and blood other or whatever of individuals, it was quantified in terms of impedance change, correlation coefficient and SNR Our results showed the optimum electrode pair (1,9) which could detect impedance changes due to the increase of the intensity in the abdominal pressure. The correlation coefficient and quadratic function between the RMS values of EMG and the impedance changes were 0.87 and $y=0.0014x^2+0.0620x+0.6958$, respectively. Thus, our system demonstrated that the abdominal pressure could be measured noninvasively and conveniently by simply estimating bio-impedance values. We propose that this optimum electrode configuration would be useful for the future studies involving the handy measurements of abdominal pressure with our suggested ambulatory urodynamics monitoring system.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.56 no.6
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• pp.1139-1143
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• 2007

For the possible application of monitoring or diagnosing heart sounds in an ubiquitous healthcare environment. a small and light electro-stethoscope that can be attached in human body should be exploited. With this aim, this study proposes a new style of electro-stethoscope device that is composed of four hardware modules in wearable style. For this ambulatory heart sound collecting device, the several tests must be performed to check portability and material capability for collecting heart sounds. It turned out to be that the multi-channel electro-stethoscope can detect heart sound signals well even if it is not pinpointed in the accurate stethoscope point on a heart. Consequently, our ambulatory electro-stethoscope hardware system can be applied to monitor or diagnose abnormal heart sounds in the ubiquitous healthcare system.

• Proceedings of the KIEE Conference
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• 2007.04a
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• pp.43-45
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• 2007

We developed a portable urodynamics monitoring system using personal digital assistance (PDA) and proposed a new method for measuring the abdominal pressure in non invasive mode using surface EMG signals. This system is consisted of a signal conditioning and control module and could measure the vesical, abdominal and detrusor pressure. The result showed a high correlation coefficient between the practical abdominal pressure, using a conventional rectal catheter and the estimated values, by our proposed algorithm (r=0.81). This system should prove a useful tool in the future evaluations of ambulatory urodynamics monitoring study.

• Journal of agricultural medicine and community health
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• v.36 no.3
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• pp.157-166
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• 2011

Objectives: Anxiety and depression are known to be associated with hypertension, and blood pressure can vary spontaneously throughout the day. The aim of this study was to evaluate anxiety, depression and 24-hour ambulatory blood pressure (24-h ambulatory BP) in employees at their worksite. Methods: A total of 107 volunteers among 136 employees at a hotel in Gyeongju, Korea were enrolled in this study between December 2009 and March 2010. The Beck Anxiety Inventory (BAI) and the Beck Depression Inventory (BDI) were used to assess anxiety and depression, respectively. Blood pressure was measured using a 24-h ambulatory BP monitoring system. Results: No significant differences in either BAI or BDI scores were found when hypertensive individuals were compared to normotensive individuals. The frequency of diastolic non-dipper was significantly higher in individuals with depressive symptoms compared to those without (p<0.05). Depression was significantly associated with diastolic non-dipper (OR: 6.85, 95% CI: 1.50-30.01). Conclusions: The results of this study indicate that depression should be considered when deciding upon blood pressure control regimens, and appropriate additive psychotherapy may be beneficial in the treatment of hypertensive patients.