• Journal of Magnetics
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• v.16 no.4
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• pp.449-452
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• 2011

A wrist wearable cuffless pulsimeter with a portable and small size apparatus using Hall effect is fabricated. The analysis of the pulse wave measured by the testing product of pulsimeter is done to measure the pulse rate and blood pressure. The blood pressure obtained by the puslimeter is compared with the practical values measured by electronic or mercury liquid blood pressure meters. The detail analysis of a pulse wave measured by a wrist wearable cuffless pulsimeter detecting the changes of the magnetic field can be used to develop a new diagnostic algorithm of blood pressure applying for oriental medical apparatus.

• Journal of the Korean Magnetics Society
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• v.20 no.3
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• pp.106-113
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• 2010

In order to get the precise blood pressure and pulse number in the cuffless status, the wrist wearable pulsimeter with a portable and small size apparatus using by Hall device is developed. The regression analysis of the pulse wave measured by the testing product of pulsimeter is conducted two equations of the blood pressure algorithm. The estimated values of blood pressure obtained by the cuffless pulsimeter during 5 s are compared with the practical values measured by electronic or mercury liquid blood pressure meters. The standard deviation of the estimated value and the practical value for the high blood pressure and the low blood pressure were 12.1 and 5.9, respectively, which have the neighborhood values of BP International Standard. The detail analysis of a pulse wave measured by cuffless wrist wearable detecting the changes of the magnetic field can be used to develop a new diagnostic algorithm of blood pressure applying for oriental medical apparatus like as the wrist wearable pulsimeter.

• Proceedings of the IEEK Conference
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• 2006.06a
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• pp.859-860
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• 2006

We developed a cuffless and noninvasive measurement technique of blood pressure using tonometric pressure sensor. With observation that the maximum value of pulse pressure is not obtained at mean arterial pressure(MAP), we have figured out MAP based on the physiological characteristic including the elasticity of wrist tisse. Detecting only one part of the body and using only one device are quite advantageous over other BP measurement techniques. Our technique makes new way for the cuffless BP measurement.

• Journal of Sensor Science and Technology
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• v.26 no.4
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• pp.239-244
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• 2017

Noninvasive, cuffless, and continuous blood pressure (BP) monitoring is essential to prevent and control hypertension. A well-known existing method for this measurement is pulse transit time (PTT), which has been investigated by many researchers as a promising approach. However, the fundamental principle of the PTT method is based on the time interval taken by a pulse wave to propagate between the proximal and distal arterial sites. Consequently, this method needs an independent system with two devices placed at two different sites, which is a problem. Even though some studies attempted to synchronize the system, it is bulky and inconvenient by contemporary standards. To find a more sensitive method to be used in a BP measurement device, this study used radial electrical bioimpedance (REB) as a potential indicator for BP determination. Only one impedance plethysmography channel at the wrist is performed for demonstrating a ubiquitous BP wearable device. The experiment was evaluated on eight healthy subjects with the ambulatory BP monitor on the upper arm as a reference. The results demonstrated the potential of the proposed method by the correlation of estimated systolic (SBP) and diastolic (DBP) BP against the reference at $0.84{\pm}0.05$ and $0.83{\pm}0.05$, respectively. REB also tracked the DBP well with a root-mean-squared-error of $7.5{\pm}1.35mmHg$.

• Journal of Korea Society of Industrial Information Systems
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• v.25 no.3
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• pp.1-10
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• 2020

In this paper, we propose an algorithm for estimating blood pressure using ECG (Electrocardiogram) and PPG (Photoplethysmography) signals. To estimate the BP (Blood pressure), we generate a periodic input signal, remove the noise according to the differential and threshold methods, and then estimate the systolic and diastolic blood pressures based on the convolutional neural network. We used 49 patient data of 3.1GB in the MIMIC database. As a result, it was found that the prediction error (RMSE) of systolic BP was 5.80mmHg, and the prediction error of diastolic BP was 2.78mmHg. This result confirms that the performance of class A is satisfied with the existing BP monitor evaluation method proposed by the British High Blood Pressure Association.

• Journal of the Korean Magnetics Society
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• v.21 no.3
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• pp.104-107
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• 2011

We measured signals at the "Guan" region of a radially arterial pulse using the prototype of a clamping pulsimeter equipped with a Hall effect device, which is passed signals through the voltage detecting hard ware system. The important four different measuring times of the period, systolic, reflective, and notch peaks for a temporally pulse signal are obtained and compared each other from the analysis for an arbitrary pulse wave of one position of small size permanent magnet. It is possible to measure the reproducible pulse rate and blood pressure by using the cuffless clip type pulsimeter without an unpleasant oppressive feeling due to the use of pressurization.

• Journal of Biomedical Engineering Research
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• v.27 no.1
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• pp.1-5
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• 2006

In this paper, we propose a subject-independent regression model to estimate systolic blood pressures (SBP) conveniently and continuously. There have been several researches on estimating SBP with pulse transit time (PTT) and they showed promising results. However, previous studies used only PTT as the estimation parameter, and their models were generated with just one person's PTT data which is not applicable to estimating other person's SBP. Therefore, we collected several additional biometric parameters with 202 healthy subjects. After statistical analysis of measured biometric parameters with SBP, we chose final estimating parameters including PTT to generate a multiple linear regression model for estimating SBP. Comparing the results of our study with approvable standards of automated sphygmomanometers developed by Association for the Advancement of Medical Instrumentation and approved by American National Standards Institute (ANSI/AAMI) indicates that our proposed method for continuously blood pressures monitoring gives an acceptable error.

• Journal of Biomedical Engineering Research
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• v.25 no.6
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• pp.605-609
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• 2004

Blood pressure (BP) is one of the important physiological parameters for diagnosing cardiovascula diseases by means of noninvasive method. Existing noninvasive methods for measuring arterial BP have to use cuff and difficult in measuring arterial BP continuously. Systolic blood pressure (SBP) and pulse transit time (PTT) have a kind of inverse relationship. We acquired PTT data when subjects were in relaxation and also after exercise. We performed the linear regression analysis for making the regression equations for each subject and the regression equation for all subjects. We compared the estimated SBP with the measured SBP to check the accuracy of our regression equations. From the result, the regression equations for each subject was appropriate according to the American National Standards Institute of the Association of the Advancement of Medical Instrument (ANSI/AAMI) which says that BP devices should have ±5mmHg mean of error and 8mmHg standard deviation of error. However, the regression equation for all subjects was not proper to ANSI/AAMI recommendation. The result means that, without cuff, we can continuously estimate each subject's SBP through PTT and indivisual calibration.