• The Journal of The Korea Institute of Intelligent Transport Systems
• /
• v.12 no.2
• /
• pp.45-51
• /
• 2013

In this paper, a driver's drowsy detection sensor system based on the respiration is investigated. The sensor system consists of a piezoelectric pressure sensor attached at the abdominal region of the seat belt and a personal computer. The piezoelectric pressure sensor was utilized for the measurement of pressure variations induced by the movement of the driver abdomen during breathing. The signal processing software for detecting driver's drowsiness was produced using the Labview. The experiments were performed with 30 years male driver. The amplitude of the respiration at awake state was larger than one at the drowsy state. On the contrary, the respiration rate at awake state was lower than one at the drowsy state. The drowsy detection sensor system developed based on the experimental could successfully detect the driver's drowsy on real-time.

• Investigative Magnetic Resonance Imaging
• /
• v.21 no.1
• /
• pp.28-33
• /
• 2017

Purpose: To investigate and compensate the effects of respiration-induced B0 variations on fat quantification of the bone marrow in the lumbar spine. Materials and Methods: Multi-echo gradient echo images with navigator echoes were obtained from eight healthy volunteers at 3T clinical scanner. Using navigator echo data, respiration-induced B0 variations were measured and compensated. Fat fraction maps were estimated using $T2^*$-IDEAL algorithm from the uncompensated and compensated images. For manually drawn bone marrow regions, the estimated B0 variations and the calculated fat fractions (before and after compensations) were analyzed. Results: An increase of temporal B0 variations from inferior level to superior levels was observed for all subjects. After compensation using navigator echo data, the effects of the B0 variations were reduced in gradient echo images. The calculated fat fractions show significant differences (P < 0.05) in L1 and L3 between the uncompensated and the compensated. Conclusion: The results of this study raise the need for considering respiration-induced B0 variations for accurate fat quantification using gradient echo images in the lumbar spine. The use of navigator echo data can be an effective way for the reduction of the effects of respiratory motion on the quantification.

• Journal of Korean Society of Forest Science
• /
• v.95 no.2
• /
• pp.168-173
• /
• 2006

Stem respiration rate ($R_{stem}$) was examined using an open flow system on black locust (Robinia pseudoacacia L.). $R_{stem}$ exponentially increased with increasing air and stem temperature during measurement period and was most closely correlated with stem temperature. It was more closely correlated with stem temperature observed 0.5-2.0 hrs earlier than with current stem temperature, that is, there was time lag between the increase of stem temperature and the efflux of $CO_2$ from stem. $R_{stem}$ gradually increased from spring to summer, and then decreased during autumn. $R_{stem}$ ranged from 0.13 to $4.44{\mu}mol$ $CO_2m^{-2}s^{-1}$. $Q_{10}$ decreased with increasing stem temperature, and varied along position (or diameter) within trees during the same period, especially during the growing season. On the other hand, time lag was shortened with increasing temperature.

• Speech Sciences
• /
• v.13 no.3
• /
• pp.133-149
• /
• 2006

This study attempted to compare acoustic parameters, physiological observation and perceptual evaluation values obtained from the treatment and control groups in order to find out which of the self voice feedback therapies was better and which methods to train them were more effective. The experimental group carried out various self voice feedback therapies while the control group did only vocal hygiene. The acoustic measurement and voice manipulation for providing the patients visual, auditory feedback were done by a speech analysis software, Praat. The authors designed vocal hygiene, abdominal respiration and Praat self voice feedback therapies and applied them to 15 patients while applying only one vocal hygiene to 15 of the control group. For the purpose of examining the degree of their voice improvement after the treatment, pre- mid- and final evaluations were made for the two groups at the beginning, the 6th week and immediately after the 8th treatment session. Results of this study were as follows: The treatment group showed much improvement after receiving the voice treatment. In particular, acoustical and physiological indices from the optical endoscopy, pitch variation(Jitter), amplitude variation (Shimmer), maximum phonation time(MPT), and psychoacoustic evaluation showed statistically significant improvements over the control groups.

• Journal of Sensor Science and Technology
• /
• v.27 no.6
• /
• pp.407-413
• /
• 2018

Most sleep apnea patients exhibit severe snoring, and long-lasting sleep apnea may cause insomnia, hypertension, cardiovascular diseases, stroke, and other diseases. Although polysomnography is the typical sleep diagnostic method to accurately diagnose sleep apnea by measuring a variety of bio-signals that occur during sleep, it is inconvenient as the patient has to sleep with attached electrodes at the hospital for the diagnosis. In this study, a diagnostic pillow is designed to measure respiration, heart rate, and snoring during sleep, using only one polyvinylidene fluoride (PVDF) sensor. A PVDF sensor with piezoelectric properties was inserted into a specially made instrument to extract accurate signals regardless of the posture during sleep. Wavelet analysis was used to identify the extractability and frequency domain signals of respiration, heart rate, and snoring from the signals generated by the PVDF sensor. In particular, to separate the respiratory signal in the 0.2~0.5 Hz frequency region, wavelet analysis was performed after removing 1~2 Hz frequency components. In addition, signals for respiration, heart rate, and snoring were separated from the PVDF sensor signal through a Butterworth filter and median filter based on the information obtained from the wavelet analysis. Moreover, the possibility of measuring sleep apnea from these separated signals was confirmed. To verify the usefulness of this study, data obtained during sleeping was used.

• Journal of the Institute of Electronics Engineers of Korea SC
• /
• v.47 no.5
• /
• pp.33-42
• /
• 2010

In this study, we have proposed a simple cardiorespiratory monitoring method based on displacements of human body which occurs due to periodic heartbeat and breathing. The proposed system consists of an aircushion, pressure sensing hardware and heartbeat and respiration signals extraction algorithm. The aircushion was used for unconstrained measurement of the respiration and heartbeats without a sensor attached on the subject's skin surface. The displacements of subject sitting on the aircushion cause small pressure variations. These variations are amplified and filtered with the pressure sensing hardware. Finally, heart rate and respiration rate are extracted by signal processing algorithm based on frequency domain filter. To evaluate the performance, extracted respiration and heart rate from proposed system were compared with conventional methods. The average sensitivity of respiration and heart rate are 98.67% and 99.24%, respectively. These results show the proposed method has advantages of installing and processing simplicity so as to be used easily in unconstrained respiration and heart rate monitoring in daily life.

• Proceedings of the KIEE Conference
• /
• 2005.05a
• /
• pp.42-44
• /
• 2005

Many cellular phone volunteer studies have been conducted since such a social issue is raised that the long time usage of cellular phone may increase health risk. While there were various volunteer studies using GSM cellular phone on heart rate and blood pressure at abroad, very few studies using CDMA phone were conducted in domestic and abroad. In this study, the volunteer groups of 21 adults were exposed at 300 mW for half an hour, and the physiological parameters such as blood pressure, heart rate, respiration rate, and skin impedance were measured. All the parameters' results did not reveal any differences between exposure and non-exposure conditions in adults.

• Science of Emotion and Sensibility
• /
• v.1 no.2
• /
• pp.113-119
• /
• 1998

A new device introducing brief pulses of odorozed air synchronized with subject's respiration to human subjects creating a positive response was developed. By the using superimposition technique of an evoked potential the positive responses to skatole in normal subject's were distinguishable. The odorant pulse trigger was the subject's respiration. Responses to aerosolized skatole consisted mainly of a positive wave with a peak latency of approximately 150 ms. In our cases, saturation of responses was found after 4-5 averagings with the responses becoming most clear after 7-8 averagings. And in cases of Alzheimer disease very quick adaptation was recognized.

• Journal of Plant Biology
• /
• v.17 no.1
• /
• pp.3-8
• /
• 1974

The experiments were conducted to examine the effects of sulfur dioxide on catalase activity in germinating seeds under dark conditions and in green plants under light conditions. Three kinds of plants, bean (Glycine max M.), cabbage (Brassica oleracea L. Chungbang No.1) and rice (Oryza sativa L. Suwon No.213-1) were used in this study. Both thegerminating seeds and the leaves were treated with various concentrations of sulfur dioxide for both one green plants with two and twelve hours. In the results of the measurement of catalase activity it was found that plant injuries by sulfur dioxide for the period of photosynthesis were higher than those for the period of respiration. In the control, apparent catalase activity under the light condition of photosynthesis showed a considerable decrease in comparison with catalase activity under the dark condition of respiration. This tendency also appeared markedly in the gas treatment. In the gas treatment for twelve hours, the decrease of catalase activity was higher than that of one hour in both photosynthesis and respiraton. It was thought that sulfur dioxide was an inhibitor of catalase activity in higher concentration of the gas.

• Proceedings of the Korean Society of Medical Physics Conference
• /
• 2002.09a
• /
• pp.90-93
• /
• 2002

In particle radiotherapy, a shape of the beam to conform the irradiation field is statically defined by the compensator, collimator and potal devices at the outside of the patient body. However the target such as lung or liver cancer moves along with respiration. This increases the irradiated volume of normal tissue. Prior discussions about organ motions along with respiration have been mainly focused on inferior-superior movement that was usually perpendicular to beam axis. On the other hand, the change of the target depth along the beam axis is very important especially in particle radiotherapy, because the range end of beam (Bragg peak) is so sharp as to be matched to distal edge of the target. In treatment planning, the range of the particle beam inside the body is calculated using a calibration curve relating CT number and water equivalent path length (WEL) to correct the inhomogeneities of tissues. The variation in CT number along the beam path would cause the uncertainties of range calculation at treatment planning for particle radiotherapy. To estimate the uncertainties of the range calculation associated with patient breathing, we proposed the method using sequential CT images with respiration waveform, and analyzed organ motions and WELs at patients that had lung or liver cancer. The variation of the depth along the beam path was presented in WEL rather than geometrical length. In analyzed cases, WELs around the diaphragm were remarkably changed depending on the respiration, and the magnitude of these WEL variations was almost comparable to inferior-superior movement of diaphragm. The variation of WEL around the lung was influenced by heartbeat.