• Proceedings of the IEEK Conference
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• 2005.11a
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• pp.489-492
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• 2005

Even though the blood pressure is one of the most widely used index for the healthcare monitoring of hypertensive and normotensive persons, there is no non-intrusive measurement method which is commercialized until now. Pulse Arrival Time (PAT) is known that it has close relation with the systolic blood pressure (SBP) and arterial stiffness. In this study, SBP estimation methods by non-intrusive measurement of PAT are suggested. For the unconstrained measurement of PAT, the first method used the electrically non contact electrocardiogram (ENC-ECG) technique and the reflective type of Photoplethysmography (PPG) sensor on the computer mouse. In the second method, ENC-ECG and the air pressure sensor in the seat cushion on a chair were measured. The third method used ECG electrodes and PPG sensors on the toilet seat cover. The validation and regression analysis of the relationship of PAT and SBP are summarized. These methods have considerable errors to be used for all people. But these can be applied for each subject after the parameter customization within acceptable error. So, it is feasible for suggested methods to be used for monitoring of SBP in daily life in non-intrusive way when there is personal identification system of each subject.

• Clinical and Experimental Pediatrics
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• v.51 no.6
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• pp.604-609
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• 2008

Purpose : Obesity in children and adolescence is highly correlated with adult obesity, which can provoke hypertension. Therefore, it is important to evaluate the blood pressure of obese children regularly. In this study, the results of ambulatory blood pressure monitoring (ABPM) in obese children and adolescents were evaluated. Methods : ABPM was conducted for selected patients who visited Handong University Sunlin Hospital from Feb. 1, 2006 to Dec. 1, 2007. The patients were classified into 3 groups: group 1 was normal, group 2 had normal casual blood pressure and a body mass index over the 95th percentile, and group 3 had high casual blood pressure over 120/80 mm Hg and a body mass index over the 95th percentile. Systolic and diastolic 24-hour blood pressure was measured, including both day and night. Results : There were 49 patients in the study. The results showed a significant difference for average systolic blood pressure between the three groups ($105.1{\pm}4.7$, $111.0{\pm}7.1$, $117.8{\pm}6.6mmHg$, P<0.001), but for average diastolic blood pressure only between groups 1 and 3 ($69.1{\pm}5.3$, $77.9{\pm}6.3mmHg$, P=0.001). In the daytime, only groups 1 and 3 showed a statistically significant difference for systolic and diastolic blood pressure. During the night the systolic pressure of group 3 was significantly higher than the other groups, but the diastolic pressure of group 3 was only higher than that group 1. No statistical difference was found in night dips among the groups. Conclusion : Ambulatory blood pressure monitoring in children and adolescents showed statistically higher blood pressure in obese patients with high casual blood pressure.

• Journal of Biomedical Engineering Research
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• v.45 no.1
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• pp.49-55
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• 2024

Accurate measurement of blood pressure is essential for classifying an individual's disease, identifying blood pressure-related risks, and managing health. Due to the environmental and health hazards of mercury sphygmomanometers, automatic sphygmomanometers using the oscillometric method are widely used in hospitals as well as in general homes, and have established themselves as a practical standard sphygmomanometer. In this study, we developed a blood pressure simulator using an actuator that provides simulated pressure to an automatic blood pressure cuff. The developed blood pressure simulator adopts an arm-shaped cylindrical shape similar to the situation in which a person measures blood pressure with an automatic blood pressure monitor, and implements a method of transmitting pressure to the cuff using a pressure plate. Accuracy was evaluated through the mean and standard deviation of the difference with the commercialized blood pressure simulator BP PUMP 2, and reproducibility was confirmed using two automatic blood pressure monitors. The developed blood pressure simulator enables automatic blood pressure monitoring in a simple manner and also meets the evaluation standards for accuracy and reproducibility. In the future, as a standardized blood pressure simulator, it is expected to be of great help in evaluating and verifying the performance of automatic blood pressure monitors by supplementing precise hardware and software and building a blood pressure database.

• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.834-837
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• 2005

In this paper, we describe the method of non-invasive blood pressure measurement using pulse wave transit time(PWTT). PWTT is a new parameter involved with a vascular that can indicate the change of BP. PWTT is measured by continuous monitoring of ECG and pulse wave. No additional sensors or modules are required. In many cases, the change of PWTT correlates with the change of BP. We measure pulse wave using the photo plethysmograph(PPG) sensor in an earlobe and we measure ECG using the ECG monitoring device our made in the chest. The measurement device for detecting pulse wave consists of infrared LED for transmitted light illumination, pin photodiode as light detector, amplifier and filter. We composed 0.5Hz high pass, 60Hz notch and 10Hz low pass filter. ECG measurement device consists of multiplexer, amplifier, filter, micro-controller and RF module. After amplification and filtering, ECG signal and pulse wave is fed through micro-controller. We performed the initial work towards the development of ambulatory BP monitoring system using PWTT. An earlobe is suitable place to measure PPG signal without the restraint in daily work. From the results, we can know that the dependence of PWTT on BP is almost linear and it is possible to monitoring an individual BP continuously after the individual calibration.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.16 no.4
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• pp.1209-1223
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• 2022

Blood pressure is one of the key physiological parameters for determining human health, and can prove whether human cardiovascular function is healthy or not. In general, what we call blood pressure refers to arterial blood pressure. Blood pressure fluctuates greatly and, due to the influence of various factors, even varies with each heartbeat. Therefore, achievement of continuous blood pressure measurement is particularly important for more accurate diagnosis. It is difficult to achieve long-term continuous blood pressure monitoring with traditional measurement methods due to the continuous wear of measuring instruments. On the other hand, radar technology is not easily affected by environmental factors and is capable of strong penetration. In this study, by using machine learning, tried to develop a linear blood pressure prediction model using data from a public database. The radar sensor evaluates the measured object, obtains the pulse waveform data, calculates the pulse transmission time, and obtains the blood pressure data through linear model regression analysis. Confirm its availability to facilitate follow-up research, such as integrating other sensors, collecting temperature, heartbeat, respiratory pulse and other data, and seeking medical treatment in time in case of abnormalities.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.25 no.6
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• pp.445-450
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• 2012

We have developed an implantable wireless sensor for real time pressure monitoring of blood circulation system. MEMS (micro-electro-mechanical system) technology was adopted as a sensor development method. The sensor is composed of photolithographically patterned inductors and a distributed capacitor in gap between the inductors. A resulting LC resonant system produces its resonant frequency in range of 269 to 284 MHz at 740 mmHg. To read the resonant frequency changed by blood pressure variation, we developed a custom readout system based on a network analyzer functionality. The bench-top testing of the pressure sensors showed good mechanical and electrical functionality. A sensor was implanted into tibial artery of farm pig, and interrogated wirelessly with accurate readings of blood pressure. After 45 days, the sensor's electrical response and histopathology were studied with good frequency reading and biocompatibility.

• Journal of the Optical Society of Korea
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• v.10 no.2
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• pp.91-95
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• 2006

Blood pressure was predicted from photoplethysmography (PPG). To obtain PPG, backscattered light from a fingertip was measured and its waveform was analyzed. Systolic upstroke time and diastolic time in the pulse waveform were used as parameters to predict blood pressure. The experiment was carried out with five subjects on five different days. The systolic upstroke time had a correlation coefficient of -0.605 with respect to systolic blood pressure and the diastolic time had a correlation coefficients of -0.764 for diastolic pressure. This PPG method does not require an air-cuff installation on the arm and can predict blood pressure continuously. This simple LED/photo detector setup can be a good candidate for nonconstrained monitoring of blood pressure variations.

• Journal of Biomedical Engineering Research
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• v.25 no.6
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• pp.599-604
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• 2004

Implantable flexible sensor using polymer/metal multilayer processing technique for telemetrical real-time blood pressure monitoring is presented. The realized sensor is mechanically flexible, which can be less invasively implanted and attached on the outside of blood vessel to monitor the variation of blood pressure. Therefore, unlike conventional detecting methods which install sensor on the inside of vessel, the suggested monitoring method can monitor the relative blood pressure without injuring blood vessel. The major factor of sudden death of adults is a disease of artery like angina pectoris and myocardial infarction. A disease of circulatory system resulted from vessel occlusion by plaque can be preventable and treatable early through continuous blood pressure monitoring. The procedure of suggested new method for monitoring variation of blood pressure is as follows. First, integrated sensor is attached to the outer wall of blood vessel. Second, it detects mechanical contraction and expansion of blood vessel. And then, reader antenna recognizes it using telemetrical method as the relative variation of blood pressure. There are not any active devices in the sensor system; therefore, the transmission of energy and signal depends on the principle of mutual inductance between internal antenna of LC resonator and external antenna of reader. To confirm the feasibility of the sensing mechanism, in vitro experiment using silicone rubber tubing and blood is practiced. First of all, pressure is applied to the silicone tubing which is filled by blood. Then the shift of resonant frequency with the change of applied pressure is measured. The frequency of 2.4 MHz is varied while the applied pressure is changed from 0 to 213.3 kPa. Therefore, the sensitivity of implantable blood pressure is 11.25 kHz/kPa.

• Journal of The Korean Dental Society of Anesthesiology
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• v.7 no.2
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• pp.126-130
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• 2007

Sedation is often indicated for the relief of anxiety for outpatient oral surgery. In combination with local anesthesia, it is safe and effective method of treatment. However, it is not always effective in allowing the physician to complete the planned oral surgery procedure. On occasion, a procedure is left unfinished due to patient combativeness and discomfort and hypertension in spite of increase in sedative doses. Episodic increases in blood pressure were most commonly caused by light anesthesia or sedation and by the patient's experience of pain during treatment. Female patient was 42 years old. blood pressure is 150/90 mmHg. Extraction and implant surgery was done under IV sedation. During seadtion, her blood pressure was increased (200/100 mmHg). Surgery was stopped. She was done monitoring blood pressure. The blood pressure was decreased to 130/90 mmHg. Sedation was failed due to significant hypertension. Blood pressure is seldom increased during sedation but we should evaluate the patient's medical history and know guideline for hypertension crisis.

• Journal of Information Technology Services
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• v.7 no.2
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• pp.113-125
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• 2008

To test if the developed ubiquitous health care devices working well and vital information could be collected and monitored systematically through internet and to test if the devices and services could be used further. Kyungwon University, KT Co., Gil Medical Center, LIG Nex1 Co., and Sujeong Health Center conducted an ubiquitous health care demonstration project in Sujeong-Gu, Sungnam, Korea from Mar. 5 to May 16. We developed and applied several medical devices to monitor health of the elderly in their houses through internet. The devices were sphygmomanometer, glucometer, body fat scale, Health Pad, and activity sensor. We distributed the devices to 20 recipients of home care and 7 diabetes patients. After received the devices and were explained how to use them, they used the devices in their houses. The vital signs of the residents were monitored through internet. A nurse monitored and consulted their vital signs in the monitoring center in Kyungwon University during the demonstration period. The consultant called them and consulted on their blood pressure, blood sugar level, and body fat after a few seconds they used the devices as well as provision of recommended contents such as diets and activities through Health Pad. To investigate cognition and satisfaction of the participants for the devices, we surveyed the participants at the end of the demonstration period. For the change in blood pressure, blood sugar level, and activities, we conducted statistical test. After the demonstration period. cognition and satisfaction for the devices and change in blood pressure, blood sugar level, and activities were evaluated. Most of the participants were acknowledged how to use the device and satisfied with the use of the devices. The internet monitoring and services are considered to be promising because most of the participants were satisfied especially because somebody was monitoring their health status. However some weaknesses such as short battery life of the activity sensor, lack of connection of consultations with hospitals, and low understanding on usage of some of the devices need to be complemented.