• Journal of the Korean Society of Clothing and Textiles
• /
• v.34 no.1
• /
• pp.112-125
• /
• 2010

A Holter monitor is used for ECG monitoring of ambulatory daily life in hospital. However, the use of this apparatus causes skin allergies and discomfort in patients because of the attachment gel and tapes used to attach disposable electrodes to the skin. In this study, the development of tight-fitting clothing connected to a portable Holter monitor was proposed. In addition, the use of conductive fabrics as electrodes was proposed; this will enable the use of garments in u-health care for measuring ECG signals. The male subjects were university students in the ages of 20 to 24. Subjective wear sensations of the experimental garments were rated using seven Likert scales. A Likert type scale was used for the evaluation and a 7 point score indicates that it provided the best fit as a tight-fitting upper clothing. Clothing pressure was measured using an air-pack-type pressure sensor (model AMI 3037-2) at 4 locations (the conductive fabric electrode) As results, a male basic sloper for upper clothing was developed and that pattern was manipulated to the tight fit pattern by considering the reduction rate of the percentage stretch in the fabric. The developed tight-fitting garment was superior in terms of subjective sensation and 6t. The mean pressure of the garment with reduction rates of 40% in width and of 50% in length was 8.45gf/$cm^2$. A conductive fabric electrode was developed by considering the sewing method and the developed electrode was detected well. The ECG data were recorded for 13 hr 19 min 44 sec and the artifacts in the ECG signals were recorded for 9 hr 3 min 46 sec (total time: 22 hr 23 min 23 sec). The artifacts data were obtained during heavy activities.

• Korean Journal of Oriental Medicine
• /
• v.13 no.3
• /
• pp.97-103
• /
• 2007

The object of this study is to evaluate confounding effect of sleeping behavior on heart rate variability (HRV) in healthy volunteers during a randomized clinical trial. From 6 healthy volunteer, we acquired circadian electrocardiography(ECG) with a Holter monitoring device(DigiTrak Plus, Philips). The compatible analytical program, Zymed, was used for calculation of RR intervals of 24h ECG signal. Then, we generated HRV signals and calculated 9 HRV parameters in time domain and frequency domain for every 30 minute with Matlab 6.x software. We also encoded participants' activities as follows; stable condition(1), sleeping behavior(2), eating behavior(3), and undefined condition(4). Using SPSS 12.0, we tested if there was any difference between HRV parameters of day-time and night-time and between those of a subject in stable condition and in sleeping behavior. As a result, one of the most important parameter-LF/HF ratio, which indicates the autonomic balance between sympathetic and parasympathetic nervous systems, as same the other parameters, showed large inter-individual variations in circadian profiles. And, the mean LF/HF ratio of each participant was different between in stable condition and in sleeping behavior (p<.05). Consequently, the effect of sleeping behavior must be considered when one or more of HRV parameters, especially LF/HF ratio, are used as assessment index in clinical studies.

• Tuberculosis and Respiratory Diseases
• /
• v.46 no.5
• /
• pp.645-653
• /
• 1999

Introduction : Although myocardial ischemia tends to occur more frequently than can he documented in ventilated patients, it has not been well studied on the factors related to the occurrence of the ischemia. Methods : To investigate the related factors to ischemia development, a prospective study was done in 95 cases with consecutive 73 patients who had received mechanical ventilation(MV) in MICU. In addition to 24 h holter monitoring, echocardiogram, electrolytes, cardiac enzymes, hemodynamic, and gas exchange measurements were done within 24 h after initiation of MV in 69 cases. The measurements were repeated at weaning period in 26 cases. The ischemia was defined by the ST segment changes; up-sloping depression more than 1.5 mm or down-sloping or horizontal depression more than 1.0 mm from isoelectric baseline for 80 ms following J point. Results : Twelve patients(12.6% in 95 cases) developed ischemia in total. The incidence of ischemia development showed an increased tendency in the initial 24 hr after MV (15.9%) and in patients with left-sided heart failure found by echocardiogram (18.2%) compared with that of the weaning period (3.8%) and patients without heart failure (10.9%) (P=0.12, P=0.09, in each). There were no differences in APACHE III score, baseline ECG findings, electrolytes abnormalities, use of inotropics or bronchodilators, presence of sepsis or shock, mode of ventilation, and survival rate according to the development of ischemia. Maximal heart rates and mean arterial pressure also were not different between patients with ($137.2{\pm}30.9/min$, $82.5{\pm}15.9$ mm Hg) and without ischemia ($l29.5{\pm}29.7/min$, $83.8{\pm}17.6$ mm Hg). Conclusion : Although the incidence of myocardial ischemia was 12.6% in total, there were no clinically predictable factors to the development of ischemia during mechanical ventilation.