• Journal of Biomedical Engineering Research
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• v.37 no.1
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• pp.39-45
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• 2016

A pressure measurement system was developed to verify magnitude and position of transferred pressure on the body surface during the intermittent pneumatic compression (IPC) which is one of the most well-known methods for the prevention of deep vein thrombosis (DVT). Eighty force sensing resistors (FSR) were arranged on a mannequin leg and a hardware controller sensed, digitized, and transferred pressure data every second while IPC was being applied. Finally, sensed pressure data were color coded and visualized on the 3D model with lab-developed software. The pressure data were also saved to files for further analysis. Using this measurement system, the changing pattern of pressure was measured on the mannequin leg by changing both chamber pressure and cuff tightness. As a result, net pressure transferred onto the body surface is dependent on chamber pressure and cuff tightness. Under the same chamber pressure, the tighter a cuff was worn, the wider compressed area was and the shorter compression cycle was. Also transferred pressure was proportional to both chamber pressure and cuff tightness.

• Korean Journal of Adult Nursing
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• v.21 no.6
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• pp.570-579
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• 2009

Purpose: The aim of this research was to determine knowledge and management of tracheal tube cuffs among nurses of ICU. Methods: This descriptive survey recruited 150 nurses working at 8 different adult ICUs within 2 tertiary hospitals in Seoul. A survey questionnaire was developed to measure cuff management. The internal reliability of the tool was examined by Cronbach's ${\alpha}$. Descriptive statistics and multiple regressions were used to analyze data. Results: Among the 150 nurses, 94.0% replied that they would measure the pressure themselves. With regard to nurses' knowledge about tracheal tube cuffs, only 6% answered that they knew 'the appropriate cuff pressure'. The existence of a measuring device (p < .001), a guideline (p < .001), the level of knowledge on its related complications(p = .003), and clinical experience (p < .001) together accounted for 35.0% of the total variation in cuff management. They pointed out that the lack of time and the lack of education were major barriers to appropriate management; whereas education update was the most imperative factor for good management. Conclusion: ICU nurses have inappropriate knowledge and practice in cuff management. Therefore continuing education is necessary for better practice of tracheal tube cuff management.

• 유체기계공업학회:학술대회논문집
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• 2006.08a
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• pp.501-504
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• 2006

The estimation of the work of heart can be treated as one of the most important parameters for determining the amount of circulating blood needed for harmonious metabolism in the human body. By monitoring the work of heart, one can detect increased work load of heart and start the treatment at the early stage of CHF. Thus it is necessary to estimate the work of heart. The contractility of the left ventricle, the second important parameter for representing the motion of heart, can be estimated through information on the work of heart. In this study, the modified Windkessel model, which has been used for a measure of vascular hemodynamic impedance parameters, was adapted to estimate the work of heart.

• Journal of the Korean Society of Physical Medicine
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• v.14 no.2
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• pp.1-7
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• 2019

PURPOSE: This study was conducted to investigate effects of shoulder adduction load on rotator cuff muscles, including the infraspinatus, during the external rotation exercise of shoulder. METHODS: This study investigated 16 healthy university students from Daegu University. Before the study started, all participants understood the content of this study. They signed an informed consent form. Five electrodes for surface electromyography (sEMG) were attached to their infraspinatus, middle deltoid, posterior deltoid, upper trapezius and pectoralis major. The participants then underwent the shoulder external rotation exercise with the shoulder adduction at three loads (0 mmHg, 20 mmHg and 40 mmHg) that were controlled using a stabilizer Pressure $Bio-feedback^{TM}$ device. The surface electrodes recorded the electromyographic data during the external rotation exercise of shoulder. RESULTS: The infraspinatus was most activated when the shoulder adduction pressure was 40 mmHg during the external rotation exercise of shoulder. The infraspinatus activation significantly increased when the shoulder adduction pressure intensity increased, while the middle deltoid activation and the posterior deltoid activation significantly decreased (p<.05). CONCLUSION: In conclusion, increases in shoulder adduction load intensity during shoulder external rotation exercises can have a positive effect on the infraspinatus, which consists of rotator cuff muscles, with minimal activity in the middle and posterior deltoid.

• Journal of Biomedical Engineering Research
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• v.24 no.4
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• pp.281-286
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• 2003

Blood Pressure is one of the most fundamental Parameters which reflects physical conditions medically and the blood pressure measurement system using oscillometric method is a Non-Invasive Blood Pressure measurement device by measuring arterial Pressure through a cuff. In this paper. we designed a inflatable wrist blood pressure system which measures blood Pressure during the stepping inflation in the wrist cuff. The hardware system consists of a main power unit, a bladder in cuff unit, signal detection units, signal Processing units. a wireless data transmission unit, and a data display unit. We evaluated the reliability of this system by comparing and analyzing systolic. diastolic blood Pressure, and heart rate with other commercial blood Pressure measurement devices. Characteristic ratio values used to determine systolic and diastolic blood Pressure using MAA(Maximum Amplitude Algorithm) were 0.436 and 0.671 respectively.

• International journal of advanced smart convergence
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• v.1 no.2
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• pp.20-25
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• 2012

The oscillometric method and Korotkoff sound method are the most common ways to measure the blood pressure. A new automatic blood pressure measurement device, which uses both oscillometric method and Korotkoff method, was developed. A pressure sensor was used to obtain cuff pressure and oscillation signal, and a microphone was used to detect Korotkoff sounds. Forty-five measurements from fifteen subjects were used for analysis. Correlation coefficients between the traditional auscultatory method and Korotkoff sound method were 0.9820 and 0.9721 for the systolic and diastolic blood pressure values, respectively. Standard deviations of differences for the systolic and diastolic blood pressure values were 1.3019 and 1.4495, respectively. Correspondingly, correlation coefficients between the traditional auscultatory method and oscillometric method using newly developed algorithm were 0.9651 and 0.9136 for the systolic and diastolic blood pressure values, with the standard deviations of 1.42 and 1.73, respectively. The results showed that the newly developed algorithm for oscillometirc method provide accurate blood pressure values, moreover, Korotkoff sound method using microphone provides even higher accuracy. Therefore, a new automatic device which utilizes both oscillometric method and Korotkoff sound method would provide the accurate and reliable blood pressure values.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.3 no.1
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• pp.3-7
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• 2010

In this study, we developed a circuit device detecting korotkoff sounds of forearm electronic blood pressure monitor by digital signal. In order to test a circuit detecting signal from korotkoff sounds, systolic and diastolic pressure were compared our developed circuit device with the existing forearm electronic blood pressure monitor (Model: SE-7000, Korea). Devices for an experiment composed of a forearm cuff, a stethoscope, an amplifier, a PC with A/D board, etc. Results of korotkoff sounds was similar to a pattern of oscilometric signals from the existing forearm electronic blood pressure monitor. We thought it is possible to measure blood pressures, if blood pressures were detected precisely using signals of korotkoff sounds.

• Biomedical Engineering Letters
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• v.8 no.4
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• pp.399-404
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• 2018

The purpose of this study was to evaluate the accuracy of a mobile wireless digital automatic blood pressure monitor for clinical use and mobile health (mHealth). In this study, a manual sphygmomanometer and a digital blood pressure monitor were tested in 100 participants in a repetitive and sequential manner to measure blood pressure. The guidelines for measurement used the Korea Food & Drug Administration protocol, which reflects international standards, such as the American National Standard Institution/Association for the Advancement of Medical Instrumentation SP 10: 1992 and the British Hypertension Society protocol. Measurements were generally consistent across observers according to the measured mean ${\pm}SD$, which ranged in $0.1{\pm}2.6mmHg$ for systolic blood pressure (SBP) and $0.5{\pm}2.2mmHg$ for diastolic blood pressure (DBP). For the device and the observer, the difference in average blood pressure (mean${\pm}$SD) was $2.3{\pm}4.7mmHg$ for SBP and $2.0{\pm}4.2mmHg$ for DBP. The SBP and DBP measured in this study showed accurate measurements that satisfied all criteria, including an average difference that did not exceed 5 mmHg and a standard deviation that did not exceed 8 mmHg. The mobile wireless digital blood pressure monitor has the potential for clinical use and managing one's own health.

• The Journal of the Korea institute of electronic communication sciences
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• v.14 no.6
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• pp.1257-1264
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• 2019

The traditional cuff-based method for BP(Blood Pressure) measurement is not suitable for continuous real-time BP measurement techniques. For this reason, the previous studies estimated various blood pressures by fusion with the electrocardiography (ECG) and photoplethysmogram (PPG) sensor signals. However, conventional techniques based on PPG bio-sensing measurement face many challenging issues such as noisy supply fluctuation, small pulsation, and drifting non-pulsatile. This paper proposed a novel BP estimation methods using PPG and ECG sensors, which can be derived from the relationship between PPG and ECG using PTT(Pulse Transit Time) and PWV(Pulse Wave Velocity). Unlike conventional height ratio features, which are extracted on the basis of the peaks in the PPG and ECG waveform. The proposed method can be reliably obtained even if there are missing peaks among the sensed PPG signal. The increased reliability comes from periodical estimation of the peak-to-peak interval time using ECG and PPG. After 250,000 times trials of the blood pressure measurement, the proposed estimation technique was verified with the accuracy of ±28.5% error, compared to a commercialized BP device.

• Journal of Biomedical Engineering Research
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• v.38 no.3
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• pp.111-115
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• 2017

Blood pressure is one of the important vital signs for monitoring the medical condition of a patient. Automated NIBP(non-invasive blood pressure) monitoring devices calculate systolic and diastolic blood pressures from the oscillation in cuff pressure caused by a pulsation of an artery. To validate the NIBP devices, we developed a simulator to supply the oscillometric waveforms obtained from human subjects. The simulator provided pressure pulses to device-under-test and device readings were compared to the auscultatory references. Fully automated simulation system including OCR(optical character recognition) were developed and used for NIBP monitoring devices. The validation results using the simulator agreed well with previous clinical validation. More validation studies using the standardized oscillometric waveforms would be required for the replacement of clinical trials to validate a new automated NIBP monitoring device.