• Korean Journal of Clinical Laboratory Science
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• v.40 no.2
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• pp.129-134
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• 2008

Obstructive sleep apnea syndrome (OSAS) is occurred by apnea by the obstruction of upper trachea while sleeping, followed by repetitive drop on arterial oxygen saturation ($SpO_2$). Therefore, the present study was focused on relation between $SpO_2$ of while having difficulty in breathing and clinical characteristics of OSAS while sleeping. The study took place at Ewha women university Mokdong hospital with 149 subjects (male 121, female 28) who were examined for polysomnography (PSG) from May 2007 to February 2008. All subjects were adhered to electrodes and sensors to measure electroencephalogram (EEG), electrooculogram (EOG), chin & leg electromyogram (EMG), airflow at nasal and oral cavities, breathing movement of chest and abdominal snoring sound and $SpO_2$. Lowest $SpO_2$ in male was meaningfully low with higher body mass index (BMI), louder snoring sound and thick neck circumference (p<0.01). While mean $SpO_2$ based on the degree of AHI did not show significant difference, lowest $SpO_2$ was significantly low with high AHI (p<0.001). Also, lowest $SpO_2$ was closely correlated with BMI (r=-00.343, p<0.001), snoring sound (r=0.177, p<0.05), apnea index (r=-0.589, p<0.001), hypopnea index (r=-0.336, p<0.001) and apnea-hypopnea index (r=-0.664, p<0.001). $SpO_2$ was closely related to clinical characteristics of OSAS, like male, BMI, snoring sound and neck circumference. Also, polysomnography accompanied by recent development of sleep study is considered as critical test to diagnose OSAS, decide the severity of illness, and evaluate the treatment plan.

• Korean Journal of Clinical Laboratory Science
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• v.43 no.4
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• pp.188-193
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• 2011

Obstructive sleep apnea (OSA) is the most common type of sleep apnea and is caused by obstruction of the upper airway. Since it is closely related to sleep parameter and body indices, the study was focused on the relationship with them. The results of polysomnography (PSG) in obstructive sleep apnea was done at ENT department of Ewha women university Mokdong hospital from March to September 2010 with 52 subjects (male 35, female 17). The leads were placed to measure electroencephalogram (EEG), electrooculogram (EOG), mandibular and anterior tibialis electromyogram (EMG), airflow in nasal and oral cavity, chest and abdominal breathing pattern, snoring sound and arterial oxygen saturation ($SpO_2$) level. From sleep parameter and body indices of adult obstructive sleep apnea compared to normal adult revealed that age (p<0.01) and snoring sound (p<0.05) were increased, stage 1 sleep (p<0.01) was increased, the deeper stages (3&4) of sleep (p<0.05) were reduced. Respiratory disturbance index (RDI) (p<0.01), mean $SpO_2$ (p<0.05) and lowest $SpO_2$ (p<0.01) were also decreased. The correlation analysis from sleep parameter and body indices of OSA showed the positive correlation with age (r=0.463, p<0.001), snoring sound (r=0.278, p<0.05), stage 1 sleep (r=0.391, p<0.01) and RDI (r=0.409, p<0.01), but showed the negative correlation with the deeper stages (3&4) of sleep (r=-0.307, p<0.05), mean $SpO_2$=(r=-0.274, p<0.05) and lowest $SpO_2$ (r=-0.392, p<0.01). This study proves that obstructive sleep apnea and indices have closed related.

• Journal of Biomedical Engineering Research
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• v.36 no.6
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• pp.283-290
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• 2015

We proposed blink based online speller for the locked-in syndrome (LIS) patients, paralyzed in nearly all voluntary muscles expect for the eyes, with a simple and easy-to-use eye blink detection glasses. Electrooculogram (EOG) is the golden standard method of eye movement or blink measurement with Ag/AgCl electrodes. However, this method has several drawbacks such as skin irritation and dehydration of conductive gel. To resolve the shortcomings, we used a blink detection system based on a transparent capacitively coupled electrode, which is conductive indium tin oxide (ITO) films. The films make it possible to measure eye blink without direct skin contact and obstruction of field of view. We finally developed user-friendly blink based online speller with the blink detection system. To classify voluntary and non-voluntary blink, we used the double blink for command of the speller. The online speller experiment result with six healthy subjects shows that mean accuracy is 98.96% and letter per minute (LPM) is 4.73, which are better result by comparison with conventional P300 or auditory brain-computer interface (BCI) paradigm. The result of the experiment demonstrates the possibility of applying the proposed system as a communication method for the LIS patients.