• Journal of Biomedical Engineering Research
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• v.28 no.2
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• pp.178-186
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• 2007

This study is attempted to correct an error of electronic blood pressure meter with an optical sensor. In general, for a hospitalized patient, ECG, blood pressure, oxygen saturation, and respiration are basically measured to monitor the patient's condition. Opening of a blood vessel after it is occluded by pressurizing the cuff influences the blood flow of peripheral blood vessels as well as oscillation changes in the cuff. Blood vessels are occluded and peripheral blood flow disappears at cuff pressure above the examinee's blood pressure, while blood vessels are opened and peripheral blood flow appears again at cuff pressure under the examinee's blood pressure. Then Disappear-Appear Point Length(DAPL) of peripheral blood flow can be judged with the signal of peripheral blood flow, thus is available as a factor of error correction for electronic blood pressure meter. Also, systolic or diastolic blood pressure can be corrected with Appear-Point-Pressure(APP) of cuff pressure at a point where blood flow occurs and Appear-Maximum Pressure(AMP) of cuff pressure at the maximum amplitude point of peripheral blood flow after peripheral blood flow appears again. For verification, 27 examinees were selected, and their blood value was obtained through experimental procedure of 4 stages including induction of blood pressure change. The examinees were divided into two groups of experimental group and control group, regression analysis was conducted for experimental group, and correction of a blood pressure error was verified with optical signal by applying the regression equation calculated in experimental group to control group. As an experimental result, mean of the whole measurement errors was 5mmHg or more, which did not meet the standard fur blood pressure meter. As a result of correcting blood pressure measurements with data of DAPL, APP, and AMP as drawn out of PPG signal, systolic blood pressure, mean blood pressure, and diastolic blood pressure were $-0.6{\pm}4.4mmHg,\;-1.0{\pm}3.9mmHg$ and $-1.3{\pm}5.4mmHg$, respectively, indicating that mean of the whole measurement errors was greatly improved, and standard deviation was decreased.

• Journal of Korean Academy of Fundamentals of Nursing
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• v.1 no.1
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• pp.51-68
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• 1994

One aim of this study was to find out the difference of indirect blood pressure between the types of instruments. The difference of indirect blood pressure was measured with mercury sphygomomanometer and electronic blood pressuremeter. Another was to determine the difference of indirect blood pressure according to width of cuff and site of cuff. Indirect blood pressures were measured with the diaphragmatic side of sphygomomanometer. The subjects were 40 female volunteers, whose arm circumferences were from 22 to 34cm. The data were analyzed by SPSS-PC program and pared t-test was used. The results are summarized as follows ; 1. Mercury sphygomomanometer systolic pressure was higher(average 2.20mmhg) than electronic blood pressuremeter. It was statistically significant(p=0.026). 2. The value of Mercury sphygomomanometer diastolic pressure was lower(2.00mmhg) than electronic's. It was statistically significant(p=0.03) 3. In the mercury sphygomomanometer systolic pressure, the value of standard cuff($12{\times}23cm$) was higher(2.40mmhg) than large one's($14{\times}45cm$). It was statistically significant(p=0.007). 4. In diastolic pressure(K4), the value of standard cuff was higher(0.65mmhg) than large cuff's. It was not statistically significant(p=0.481). In K5, the value of standard cuff($12{\times}23cm$) was higher(0.55mmhg) than large cuff's. It was not statistically significant(p=0.541). 5. Difference according to site of showed that the values of systolic pressure over elbow joint were higher(20.00mmhg, 26.45mmhg) than ones at site of elbow joint. It was significant statistically(p=0.000) and clinically. 6. The values of diastolic pressure(K4) over elbow joint were higher(17.10mmhg, 21.60mmhg) than ones at site of elbow joint. It was significant statistically (p=0.000) and clinically. The values of K5 over elbow joint were higher(17.25mmhg, 22.15mmhg) than ones at site of elbow joint. It was significant statistically(p=0.000) and clinically. I think similar studies about indirect blood pressure according to diseases and positions are necessary. In addition, similar studies, are required about accuracy of method electronic blood pressuremeter according to site of mesurement.

• Journal of Biomedical Engineering Research
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• v.29 no.5
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• pp.371-375
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• 2008

In blood pressure measurement, the oscillometric method detects and analyzes the pulse pressure oscillation while deflating the cuff around the arm. For its principle, one has to inflate cuff pressure above the subject's systolic pressure and deflate below the diastolic pressure. Most of the commercialized devices inflate until the fixed target pressure and deflate until the fixed completion pressure because there is no way to know the systolic and diastolic pressure before measurement. Too high target pressure makes stress to the subject and too low target pressure makes big error or long measurement time because of re-inflation. There are similar problems for inadequate completion pressure. In this study, we suggest new algorithm to set proper target and completion pressure for each subject by analyzing pressure waveform while inflating period. We compared our proposed method and auscultation method to see the errors of estimation. The differences between the two measurements were -4.02$\pm$4.80mmHg, -10.50$\pm$10.57mmHg and -0.78$\pm$5.l7mmHg for mean arterial pressure, systolic pressure and diastolic pressure respectively. Consequently, we could set the target pressure by 30 mmHg higher than our estimation and we could stop at 20mmHg lower than our estimated diastolic pressure. Using this method, we could reduce the measurement time.

• 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.

• 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.

• Journal of Sensor Science and Technology
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• v.22 no.1
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• pp.38-43
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• 2013

In this study, the artery's compliance model and the pulsation waveform model was proposed to estimate blood pressure without applying HPF (High Pass Filter) on signal measured by the oscillometric method. The method proposed in the study considered two ways of estimating blood pressure. The first method of estimating blood pressure is by comparing and analyzing changes in pulsation waveform's dicrotic notch region during each cardiac period. The second method is by comparing and analyzing morphological changes in the pulsation waveform during each cardiac period, which occur in response to the change in pressure applied on the cuff. To implement these methods, we proposed the compliance model and the pulsation waveform model of the artery based on hemodynamic theory, and then conducted various simulations. The artery model presented in this study only took artery's compliance into account. Then, a pulsation waveform model was suggested, which uses characteristic changes in the pulsation waveform to estimate blood pressure. In addition, characteristic changes were observed in arterial volume by applying artery's pulsation waveform to the compliance model. The pulsation waveform model was suggested to estimate blood pressure using characteristic changes of the pulsation waveform in the arteries. This model was composed of the sum of sine waves and a Fourier's series in combination form up to 10th harmonics components of the sinusoidal waveform. Then characteristic of arterial volume change was observed by inputting pulsation waveform into the compliance model. The characteristic changes were also observed in the pulsation waveform by mapping the arterial volume change in accordance with applied cuff's pressure change to the pulsation waveform's change according to applied pressure changes by cuff. The systolic and diastolic blood pressures were estimated by applying positional change of pulsation waveform's dicrotic notch region.

• Journal of Sensor Science and Technology
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• v.13 no.6
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• pp.462-472
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• 2004

In this study, we measured the blood flow on arm by non-invasive method and implemented a system to measure variation of the blood flow by estimating bio-electrical impedance and arterial pressure according to cuff pressure. The implemented system measured impedance variation according to pressure variation applied by artificial cuff pressure on the measuring position. The system consisted of pressure measuring part and impedance measuring part using 4-electrode method. Pressure measuring part was composed of semiconductor pressure sensor and electronic circuit for signal processing of sensor output signal. In addition, impedance measuring part was composed of constant current source circuit and lock-in amplifier for detecting impedance signal. We conducted experiments of impedance measuring part using standard resistance for performance evaluation of the implemented system. In addition we experimented to estimate variation of the blood flow by measuring impedances of the experimental group. We estimated ratio of the blood flow resistance using mean arterial pressure and variation of the blood flow. As a result the ratio of the blood flow resistance and variation of blood flow were in an inverse relationship with each other and the correlation coefficient was -0.96776.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.5 no.7
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• pp.1263-1271
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• 2001

There are two methods in blood pressure measurement ; Invasive methode and Non-invasive method. The Invasive methode can get the 띠cod pressure measurement but, patient feel uncomfortable. So Non-invasive methode used generally. The Oscillometric method is typical Non-Invasive method. This method is commonly used to measure BP in electric sphygmomanometer and has various algorithm. In this paper it is described about a algorithm, it controls, determinates the cuff pressure, and fillers the measured BP data. This system can interface with PC(personal computer) by RS-232 and save the measured data in PC. This system deflates the cuff pressure by Solenoid valve. The main algorithm are oscillometric and maximum amplitude algorithm(MAA). MAA has various measured oscillation, it depends on patient's age, height, weight and arm circumference size. In this paper proposed system can measure Systolic BP, Diastolic BP, and Mean BP using Interpolation, Auto Reinflation algorithm.

• Journal of Korean Neurosurgical Society
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• v.39 no.6
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• pp.419-422
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• 2006

Objective : Endotracheal tube cuff-pressure[ETCP] increases significantly during anterior cervical spine surgery with neck retraction. Clinically, postoperative hoarseness with sore throat is correlated with vocal cord edema due to longer intubation time and higher ETCP during neck retraction. Methods : Fifty patients of anterior cervical spine surgery were randomized to a control [no adjustment, 25 cases] and a treatment group [ETCP adjusted to 20mmHg, 25 cases]. Patients were blinded to their group assignments. They were questioned about the presence of ischemic symptoms [sore throat, dysphagia, hoarseness] postoperatively at different time points; 4 hours, 24 hours, and 1 week postoperatively. Results : No differences between groups at 4 hours and 1 week postoperatively were demonstrated. At 24 hours, 36% of patients in the treatment group complained of sore throat while 56% of control group patients did [p < 0.05]. Female patients correlated with development of all ischemic discomfort [p < 0.05 : sore throat, hoarseness, dysphagia]. Conclusion : Our results suggest that postoperative ischemic symptom following anterior cervical spine surgery may be associated with the two predictors; increased ETCP during neck retraction and female. The simple procedure of maintaining ETCP to 20mmHg can prevent postoperative tracheal ischemic symptom.

• 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.