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This study introduces a personalized automated exercise guidance system for the efficient reduction of obesity. The proposed system was composed of wearable biometric devices and exercise-machine control systems connected with the integrated database server. It was designed for providing customized exercise prescription (intensity, repetition, frequency, etc.) according to ACSM guidelines for obesity based on real-time biosignals feedback and an individual’s exercise capacity. Nineteen subjects participated in evaluating the proposed system, and we found that the risk factors (body composition, hemodynamics, blood enzymes, and exercise variables) related to obesity were statistically significantly improved. Other exercise prescriptions for chronic diseases and symptoms will be able to adapt to the proposed system so that we believe it would be substantially helpful to improve geriatric diseases and symptoms by using technology-driven exercise.

In this paper, we suggest a method to improve the fusion of an accelerometer and gyro sensor by using a Kalman filter to produce a more high-quality respiration signal to supplement the weakness of using a single accelerometer. To evaluate our proposed algorithm’s performance, we developed a chest belt-type module. We performed experiments consisting of aerobic exercise and muscular exercises with 10 subjects. We compared the derived respiration signal from the accelerometer with that from our algorithm using the standard respiration signal from the piezoelectric sensor in the time and frequency domains during the aerobic and muscular exercises. We also analyzed the time delay to verify the synchronization between the output and standard signals. We confirmed that our algorithm improved the respiratory rate’s detection accuracy by 4.6% and 9.54% for the treadmill and leg press, respectively, which are dynamic. We also confirmed a small time delay of about 0.638 s on average. We determined that real-time monitoring of the respiration signal is possible. In conclusion, our suggested algorithm can acquire a more high-quality respiration signal in a dynamic exercise environment away from a limited static environment to provide safer and more effective exercises and improve exercise sustainability.

The impedance cardiogram has been proposed as a non-invasive, continuous, operator independent, and cost-effective method for cardiac output monitoring. However, it can not be completely considered as non-restrictive method because of attached spot and band type electrodes. Therefore, we developed a improved convenient hand-held typed measurement system for cardiac output by electrical impedance technique. 80 subjects from Yonsei University and the surrounding areas, participated. All subjects measured stroke volume and cardiac output through Physioflow and developed system. To verify the developed system, statistical methods such as correlation, Wilcoxon signed ranks test, and the Bland-Altman analysis were used. The proposed system showed significant correlation in both male and female stroke volume(r

Increasing the oxidation of fat through exercise is the recommendable method for weight control. Preceding researches have proposed increase in the usage of fat during exercise in stabilized state and under maximum exertion through aerobic training. However, such researches require additional equipment for gas analysis in order to measure the caloric value or gas exchange of subjects during exercise. Such equipments become highly restrictive for those exercise and cause substantially higher cost. According to this, we have presented the method of estimating the maximal fat oxidation point through changes in LF & HF which reflects changes in heart rate and the autonomic nervous system in order to induce exercise for a less restrictive and efficient fat oxidation than existing methods. We have conducted exercise stress test on subject with similar exercise abilities, and have detected the changes in heart rate and changes in LF & HF by measuring changes in fat oxidation and measuring ECG signals at the same time through a gas analyzer. Changes in heart rate and HRV of the subjects during exercising was detected through only the electrocardiographic signals from exercising and detected the point of maximum fat oxidation that differs from person to person. The experiment was carried out 16 healthy males, and used Modified Bruce Protocol, which is one of the methods of exercise stress test methods that use treadmill. The fat oxidation amount during exercise of all the subjects showed fat oxidation of more than 4Fkcal/min in the exercise intensity from about 5 minutes to 10 minutes. The correlation between the maximal fat oxidation point obtained through gas analysis and the point when 60% starts to be relevant in the range from -0.01 to 0.01 seconds for values of R-R interval from changes in heart rate had correlation coefficients of 0.855 in Kendall’s method and in Spearman’s rho, it showed significant results of it being p

Purpose The purpose of this study is to present method of providing optimal physical exercise effect using Heart Rate Variability (HRV; LF/HF Ratio) during step-by-step exercise load.

In this study, a new method that can estimate ICG data from a subject`s both hands to measure Cardiac Output under convenient sensor environment. With this aim, a grip-type electrode was implemented to measure ICG. To improve the accuracy of measurement, the regression equation was extracted using multiple bio-parameters and our result was compared with the thoracic ICG equipment(Physio Flow, PF104D, Manatec Biomedical, France), which is being used in clinics. The subjects consist of 26 men and 4 women(age in ). They are no cardiac disease. Parameters available for regression model were used gender, BMI, MBP, LVET, dZ/dt(max), distance between the measured electrodes, body impedance, and PTT. As a result of analyzing the ICG measurement value on thorax and both hands, the correlation with stroke volume, heart rate, and cardiac output was

The blood pressure measuring equipment, which is being supplied and used most widely by being recognized convenience and accuracy now generally, is oscillometric blood pressure monitor. However, a change in blood pressure is basically influenced by diverse elements such as each individual`s physiological status and physical condition. Thus, the measurement of blood pressure, which used single element called oscillation in blood pressure of being conveyed to cuff, is not considered on physiological elements such as cardiovascular system status and blood vessel stiffness index, and on external elements, thereby being quite in error. Accordingly, this study detected diverse bio-signals and body informations in each individual as the measurement subject such as ECG, PPG, and Korotkoff Sound in order to enhance convenience and accuracy of measuring blood pressure in the complex measurement equipment, thereby having extracted regression method for compensation in error of oscillometric blood pressure measurement on the wrist, and having improved accuracy of measuring blood pressure. To verify a method of improving accuracy, the blood pressure value in each of SBP, DBP, MAP was acquired through 4-stage experimental procedure targeting totally 51 subjects. Prior to experiment, the subjects were divided into two groups such as the experimental group for extracting regression method and the control group for verifying regression method. Its error was analyzed by comparing the reference blood pressure value, which was obtained through the auscultatory method, and the oscillometric blood pressure value on the wrist. To reduce the detected error, the blood pressure compensation regression method was calculated through multiple linear regression analysis on elements of blood pressure, individual body information, PTT, HR, K-Sound PSD change. Verification was carried out on improving significance and accuracy by applying the regression method to the data of control group. In the experimental results, as a result of confirming error on the reference blood pressure value in SBP, DBP, and MAP, which were acquired through applying regression method, the results of mmHg, mmHg, mmHg could be obtained. This is not only the numerical value of satisfying the sphygmomanometer reference of AAMI, but also shows the lower result than the numerical value in SBP : mmHg, DBP : mmHg, which is the mean error in the experimental results of Brram`s research for verifying accuracy of Omron RX-M, which shows relatively high accuracy among wrist sphygmomanometers. Thus, the blood pressure compensation could be confirmed to be made within significant level.

Wearable electrocardiogram (ECG) systems are exposed to more noises than the general ECG systems, because of the high impedance between electrodes and the skin and the need to acquire ECG data during exercise or in daily life. The purpose of this study was to enhance heart rate detection by optimizing electrode and signal processing in a wearable system during high-intensity exercise. To create an optimal electrode condition, we quantitatively measured the change in noise according to a change in pattern of textile electrodes by using 3 textile electrodes with the same material quality but different patterns. We also measured the degree of skin hydration by using an MPA5 (CK Electronics, Germany) to obtain the optimal condition between electrodes and skin. To accurately detect the QRS complex, use of an improved algorithm based on a wavelet, which has strong noise tolerance, was suggested. We obtained root-mean-square (RMS) values that were expected to be similar to those measured with the Ag-AgCl electrode at the point of >120% of skin hydration. The QRS complex detection rate of the wavelet method that was suggested in this study was compared to that of an adaptive filter and mathematical morphology operator. We used the data collected during actual exercise performed at 15 km/h. The QRS complex detection rate of the proposed algorithm was 99.9%. Through optimization of the wearable system that was suggested in this study, collection of a more accurate heart rate value is expected. In addition, the influence of noise could be minimized in the wearable system.

In this study, we attempt to design a real-time autonomic nervous system (ANS) evaluation system usable during exercise using heart instantaneous frequency (HIF). Although heart rate variability (HRV) is considered to be a representative signal widely used ANS evaluation system, the R-peak detection process must be included to obtain an HRV signal, which involves a high sampling frequency and interpolation process. In particular, it cannot accurately evaluate the ANS using HRV signals during exercise because it is difficult to detect the R-peak of electrocardiogram (ECG) signals with exposure to many noises during exercise. Therefore, in this study, we develop the ground for a system that can analyze an ANS in real-time by using the HIF signal circumventing the problem of the HRV signal during exercise. First, we compare the HRV and HIF signals in order to prove that the HIF signal is more efficient for ANS analysis than HRV signals during exercise. Further, we performed real-time ANS analysis using H1F and confirmed that the exerciser's ANS variation experiences massive surges at points of acceleration and deceleration of the treadmill (similar to HRV).

This study aims at compensation of the skin moisture level using skin impedance and SR factor. SR factor is related with the current diffusion into the skin layer. To efficiently analyze the current diffusion on the skin model, we used an electromagnetic simulation program called Ansys 10.0 Emag. We confirmed that the measured value decreases as the electric current gets more diffused to the layer below the horny layer. In order to conduct actual experiments based on the simulated result, we manufactured special electrodes with 24 pins by arranging 0.8㎜-diameter electrodes every 0.5㎜, in a 3 × 8 array. By simultaneously achieving both impedance value and SR value of skin with the manufactured electrodes, we compared the skin moisture level using the existing equipment to the skin moisture level applied using the skin impedance as well as the SR factor developed in this study. The correlation coefficient between the skin moisture level achieved from the existing equipment and the reference value was 0.615 (p＜0.01), whereas the correlation coefficient between the skin moisture achieved from the regression equation in this study was 0.677 (p＜0.01). Accordingly, it was confirmed that applying SR factor additionally improves the moisture level more precisely.

The Purpose Of This Paper Is To Use A Tactile Sensor To Compensate The Error Rate. Most Automated Sphygmomanometers Use The Oscillometric Method And Characteristic Ratio To Estimate Systolic And Diastolic Blood Pressure. However, Based On The Fact That Maximum Amplitude Of The Oscillometric Waveform And Characteristic Ratio Are Affected By Compliance Of The Aorta And Large Arteries, A Method To Measure The Artery Stiffness By Using A Tactile Sensor Was Chosen In Order To Integrate It With The Sphygmomanometer In The Future Instead Of Using Photoplethysmography. Since Tactile Sensors Have Very Weak Movements, Efforts Were Made To Maintain The Subject's Arm In A Fixed Position, And A 40hz Low Pass Filter Was Used To Eliminate Noise From The Power Source As Well As High Frequency Noise. An Analyzing Program Was Made To Get Time Delay Between The First And Second Peak Of The Averaged Digital Volume Pulse (Δt dvp ), And The Subject's Height Was Divided By Δt dvp To Calculate The Stiffness Index Of The Arteries (Si dvp ). Regression Equations Of Systolic And Diastolic Pressure Using Si dvp And Mean Arterial Pressure (Map) Were Computed From The Test Group (60 Subjects) Among A Total Of 121 Subjects (Age: 44.9±16.5, Male: Female = 40:81) And Were Tested In 61 Subjects To Compensate The Error Rate. Error Rates Considering All Subjects Were Systolic 4.62±9.39㎜hg, And Diastolic 14.40±9.62㎜hg, And Those In The Test Set Were 3.48±9.32㎜hg, And 14.34±9.67㎜hg Each. Consequently, Error Rates Were Compensated Especially In Diastolic Pressure Using Si dvp , Various Slopes From Digital Volume Pulse And Map To Systolic - 1.91±7.57㎜hg And Diastolic 0.05±7.49㎜hg.

Photoplethysmograph (PPG) has been widely used to investigate various cardiovascular conditions. Previous studies demonstrated effects of temperature of the measurement environment; however, an integrated evaluation has not been established in environments with gradual air temperature variation. The purpose of this study is to investigate variations and relationships of blood pressure (BP), PPG and cardiovascular parameters such as heart rate (HR), stroke volume (SV), cardiac output (CO) and total peripheral resistance (TPR), by changing skin surface temperature (SST). Local mild cooling and heating was conducted on 16 healthy subjects. The results showed that local SST changes affected Finometer blood pressures (Finger BP), PPG components and TPR, but not the oscillometric blood pressure (Central BP), HR, SV and CO, and indicated that temperature must be maintained and monitored to reliably evaluate cardiovascular conditions in temperature-varying environments.

Spirometry is regarded as the only effective method for detecting pulmonary function test (PFT) indices. In this study, a novel impedance pulmonary function measurement system (IPFS) is developed for directly assessing PFT indices. IPFS can obtain high resolution values and remove motion artifacts through real-time base impedance feedback. Feedback enables the detection of PFT indices using only both hands for convenience. IPFS showed no differences in the sitting, supine, and standing postures during the measurements, indicating that patient posture has no effect on IPFS. Mean distance analysis showed good agreement between the volume and flow signal of IPFS (p < 0.05). PFT indices were detected in subjects to differentiate a chronic obstructive pulmonary disease (COPD) patient group from a normal group. The forced vital capacity (FVC), forced expiratory volume in the first second (FEV1), FEV1/FVC, and peak expiratory flow (PEF) in the COPD group were lower than those in the normal group by IPFS (p < 0.05). IPFS is therefore suitable for evaluating pulmonary function in normal and COPD patients. Moreover, IPFS could be useful for periodic monitoring of existing patients diagnosed with obstructive lung disease.

In this study, we acquired video images from the index finger of subjects using white light emitting diode (WLED) of a smart phone as light source and a camera as optical detector on a frame-by-frame basis, converted the acquired images into red, green and blue (RGB) formats and detected the images in the form of photoplethysmography (PPG) waveforms through real-time video signal processing. Through utilization of secondary derivative photoplethysmography (SDPTG), a PPG second order differential form, the parameters used to monitor arterial stiffness of b/a ratio, d/a ratio and Aging Index (AI) were calculated. From the results of correlation analysis between the value calculated from smart phone and the value calculated by reference equipment, statistically significant results of b/a ratio (r=0.919, p

The analysis of the breath signal during sleep provides key information for the revelatory analysis of the clinical symptoms of sleep diseases such as sleep apnea, etc which disturbs normal sleep and further on can become the potential cause of heart diseases. This information can be used importantly for such purposes as to remove change quantity by breathing not only for the system modeling of the cardiovascular system for the function analysis of the autonomic nervous system (ANS), which is generated in the human body during sleep, but also for the accurate analysis during the analysis of the frequency of the changing rate of heartbeats, and the classification of significant electrocardiogram (ECG), which includes an accurate breath signal during sleep which has immense meaning (Park et al., 2004). In general, the methods measuring breath signals can be largely divided into a direct method and an indirect method. A direct method which measures changes of air temperature around the nose by breathing and using a spirometer suggests a standard in research and can have accurate breath signals (Cysarz et al., 2008). However, because of the disadvantage of cumbersome and inconvenient measurements, an indirect method, which can measure the breath of the examinee without binding and consciousness in a relatively simple measurement method, is more preferred. As these indirect methods, a method, which extracts breath by measuring the inductance and impedance changes of the thorax by breath or by measuring column changes of the thorax, and ECG-derived respiratory (EDR) method, which induces breath signals from ECG by using impacts of changes of impedance within the thorax on ECG according to the filling and exhausting of air within the lungs which accompanies it during breathing, have been suggested (Yi et al., 2006; Moody et al., 1985). However, in the case of using a method measuring inductance or impedance changes of the thorax or column changes of the thorax for monitoring the breath during sleeping, it can disturb the normal sleeping of the examinee because the examinee has to be put on a belt or attach an electrode on the thorax. In addition, it may be difficult to detect accurate breath because lots of noise components accompany it according to the surrounding environment. Therefore, recently, the EDR method, which extracts breath signals from the ECG measured during sleep by using the conductive textile electrode, is utilized more for detecting breath

The pulmonary function test (PFT) is a widely used test in patients or for those who are at risk of respiratory dysfunction. In this study, we aimed to develop a more convenient system, namely, the impedance pulmonary function measurement system (IPFS), for overcoming the restrictions posed by the prevalent spirometric PFT. IPFS employs tetra polar electrodes that can measure pulmonary function using the subjects' hands alone. The impedance measured by IPFS extracts AC values of pulmonary impedance from DC values of body impedance in respiration. This system yields changes in the impedance of volume and flow. In order to verify IPFS, we compared the continuous waveforms obtained from the PFT module and developed IPFS using Pearson linear correlation coefficients (p0.01) for volume and flow. Further, we evaluated the potential application of IPFS for detecting pulmonary functions such as volume (FEV(1)/FVC Ratio) and flow (PEF), and compared the measured parameters between IPFS and spirometric PFT. Our results demonstrate that the measurements obtained using IPFS reflect pulmonary function parameters.

The purpose of this study is to monitor the autonomic nervous system with average skin temperature and its variability, of which both are compared with heart rate variability. Six healthy male college students participated in a test which is composed of rest for 5 min., exercise for 20 min. and recovery for 10 min. to measure their ECG and skin temperature with BIOPACK. The test found similarity between HRV's total power and peak amplitude of skin temperature variability towards physical stress. Furthermore, the constant fall of mean temperature during exercise and recovery capacity during recovery stage also proved that subjects differ in their autonomic nervous system activities to maintain homeostasis.

This paper presents a sports health care system suitable to the fitness club environment. As improvement of quality of life, increasing interest of exercise, it has been studied and developed products briskly for exercise management. As such products are developed mainly for outdoors activity, however, it has a limitation to systematically manage exercise in consideration of fitness club environment. We want to overcome this limitation through by development of systematically exercise management system using interacting interface network. We devised system suitable to control and monitor systematic exercise using bio-module available for real-time bio-signal processing based on a novel algorithm that could reduce operation complexity when users do exercise in the fitness club environment. The overall system is composed of bio-module that can collect bio-signal information and analyze signal in real time, exercise equipment control module and exercise management server. Based on bio-signal information processed in real time, it is possible for exercise management prescription in real time according to user's health condition using organically interacting communication. We expect that our suggested system contribute to propagation and development of sports health care field.

Wearable ECG Recorder can detect not only Biosignal but also Motion artifact and other surrounding noises. This study used wavelet transform as a way of removing such noise and compared Continuous Wavelet Transform (CWT) and Discrete Wavelet Transform (DWT). Each transform is designed to optimize the QRS Complex. CWT was designed to detect the Maximum energy scale from QRS Complex. DWT was designed to decompose 8-Levels and to reconstruct detailed coefficient with the frequency of the QRS Complex. To test the performance of two methods, data were collected from MIT-BIH Arrhythmia Database and Wearable ECG Recorder(WER) at the speed of 3km/h, 6km/h, 9km/h, 12km/h. By analyzing the data from two methods, the effectiveness for detecting QRS Complex while eliminating the surrounding noises.

The purpose of this study is, for estimating energy expenditure with triaxial accelerometers during exercise, to compare determination coefficients of equations of the estimated regression according to several locations of the accelerometers on the body and then to present an estimation model on the location where there is the least restriction on physical activities. A small portable device that is able to obtain acceleration data during exercise was developed. It was attached on the back, wrist, knee and ankle of the body and then submaximal exercise was conducted on treadmills with the Bruce protocol. For the experimentation, seventeen males of twenties and thirties in good health (27.23+/-2.18) participated and wore the equipment to analyze respiratory gas, so that the values of acceleration and energy expenditure from the respiratory gas analyzer could be obtained at the same time. The energy expenditure values from the outputs of the respiratory gas equipment were set as a base value, and the accelerations and the physical features of the participants (age, weight, height and BMI) as variables, to check each correlation, and for each of the four locations of the accelerometers on the body, regression analysis was carried out. The results of the experiment are as follows: the correlation between the acceleration and the energy expenditure was the highest on the knee and the lowest on the wrist; but, the determination coefficients (R(2)) of the regression equations using the continued hours of exercise, weight and acceleration values did not show significant difference among the locations on the body, as the highest R(2) = 0.873 on the back and the lowest R(2) = 0.852 on the wrist. This study has shown two possibilities. First, it is possible to predict energy expenditure using accelerometer sensor without respiration gas analyzer in laboratory situation. Second, these findings can be applied to application ab- out predicting conveniently energy expenditure during outdoor activities using accelerometer on watch or shoes.

In this research, a device, which has a thermotherapic and massaging function and relaxes muscles, was used to evaluate the effect muscle relaxation has on stress relief. Therefore, the physiological changes namely Heart Rate (HR), Heart Rate Variability (HRV) and Skin Temperature (SKT) of the subjects which reflect the autonomic nervous system and cardiovascular relationship were obtained and analyzed. In order to evaluate the assumption that the treatment relieves the subject's physiological and psychological stress, experiment was carried out on 25 adults (13 male and 12 female, age 52.32+/-18.121) through stages consisted of relaxation, pre-treatment, treatment and post-treatment. Treatment was provided to the back, stomach and leg area by massaging 55 degrees C heat to the back. According as the physiological changes of subjects before and after treatment were compared, the present research was able to prove that thermotherapy and massage treatment induces physiological change of patients thus relieves stress.

The point of this study is on the development of wireless patient monitoring system that can monitor heart rates in real time environments. The entire system consists of a portable photoplethysmography device, a healthcare server and a Smartphone for healthcare information reports. The portable device collects heart rate information from the patients and sends the data to home healthcare server. This device is designed to be easily worn and have low power consumption. The role of the healthcare server is to analyze the collected biomedical signals. The result of the analysis is displayed on the Smartphone through the CDMA networks. The application program on Smartphone gives the healthcare information to patients and doctors. This system would be useful for patients who have chronic heart disease.

Hypotension and hypertension are chronic diseases, which can be effectively prevented and controlled by constantly monitoring. In this study, personalized healthcare comment service for hypertension patients is proposed and implemented. We have developed algorithms of health state code generation and doctor's comments for patients on case-by-case basis. This prototype service shows how such personalized comments can manage patients with hypertension using blood pressure monitor and mobile device.

Our study focuses on classifying as significant electrocardiogram (ECG) data from home healthcare system. Generally, spectral analysis of RR interval (RRI) time series is used to determine periodic component of heart rate variability (HRV). It is well known, moreover, that low frequency (LF) component is associated with heart rate variability regulation, and high frequency (HF) component is referred to respiration as respiration sinus arrhythmia (RSA) in the HRV power spectra. In many cases, however, LF and HF components may be entirely superimposed on each other and, therefore, the method by division of power spectra range can not be evaluated diagnostically. We propose another approach to interpret well better than before. The method which we suggest is that it finds high correlative data using frequency analysis comparison heart instantaneous frequency (HIF) based on extracting the instantaneous fundamental frequency with EDR. The reason which we use HIF is that it is simpler and more powerful against noise than HRV. First of all, we show the EDR extraction process, and then prove that HIF signal is useful or not through comparison with HRV. Finally, we classify significant signal data through comparison high frequency (HF) component obtained frequency analysis of HIF with that of EDR.

There is a tremendous increase in spam traffic these days. Spam messages muddle up users inbox, consume network resources, and build up DDoS attacks, spread worms and viruses. Our goal is to present a definite figure about the characteristics of spam and spammers. Since spammers change their mode of operation to counter anti spam technology, continues evaluation of the characteristics of spam and spammers technology has become mandatory. These evaluations help us to enhance the existing technology to combat spam effectively. We collected 400 thousand spam mails from a spam trap set up in a corporate mail server for a period of 14 months form January 2006 to February 2007. Spammers use common techniques to spam end users regardless of corporate server and public mail server. So we believe that our spam collection is a sample of world wide spam traffic. Studying the characteristics of this sample helps us to better understand the features of spam and spammers technology. We believe that this analysis could be useful to develop more efficient anti spam techniques.

This study intends to research and develop unrestricted measuring system and user interface in a new form to effectively collect individual bio information of car users - driver and passenger - with the systems previously researched and developed as basic platform. The whole system is designed to measure bio signals for monitoring the physiological changes in the vehicle. For system evaluation, an actual operating condition was offered by mounting and equipping the system in an actual vehicle, and then the measured information was analyzed and verified. Through these processes, the measured signals were evaluated and its availability in the vehicle was confirmed. In this study, the system to induce drivers to safe driving was developed through consecutive monitoring of fatigue and increased risk of safety accident as drivers drive for many hours. In addition, health care service system for driver and passenger was developed through the measurement of various bio signals. Besides, a case of unrestricted and unconscious bio signal measurement system was suggested with completely recognizing and understanding a special condition of driving.

Preceding studies have shown photoplethysmographic (PPG) signal resembles blood pressure (BP) wave and varies. Some investigators also have studied this relationship to explain complex hemodynamic characterization. The purpose of this study is to make a trial of finding arterial BP (ABP) using PPG signal. This new attempt is based on the theory that BP consists of the change of blood volume (BY) and the resistance of vessels. This study proposes a method to estimate BP from PPG signal and points to be considered when we use this method. Therefore we can classify cardiac output (CO) and the blood vessel resistance (VR) by analyzing PPG signal. Signals were obtained from the tails of three healthy dogs and the fingers of six patients who have changes of BP. In the animal test, we first found the correlations between PPG signal and BP, and then we could reconfirm the relationship in the clinical test. PPG signal could be influenced by the pressure (P) that occurred between the index finger and the sensor and the temperature (T) of the interest region, so we examined these influences with six healthy subjects. From the experimental results, we suggest the relationship of the estimation of BP from PPG signal. When PPG signal is normalized by P and T, this PPG signal offers more accurate estimation of BP. This study could be able to provide a new BP measurement system that has not only convenience but also accuracy.

The system proposed in this paper has been designed to acquire and transmit vital signals from lavatory-attached acquisition device in ubiquitous healthcare environment. We focused on the system to be unconstraint and non-invasive by introducing automatic measurement procedures. ECG, SpO2, NIBP, impedance and weight were measured and recorded. Detected bio-signals were evaluated and became available to the patients to check the results immediately so that the data could be sent to doctors simultaneously. For the quantitative assessment of individual user's health condition by using signals from our system, we propose to apply linear parametric system identification method which provides a means to investigate cardiovascular regulatory mechanisms.

The purpose of this paper is to use tactile sensor to compensate the error rate. Most automated sphygmomanometers use oscillometric method and characteristic ratio to estimate systolic and diastolic blood pressure. However, from the face that maximum amplitude of oscillometric waveform and characteristic ratio are affected by compliance of aorta and large arteries, a method to measure the stiffness of arteries by using tactile sensor was chosen in order to integrate it with sphygmomanometer in the future instead of using photoplethysmography. Since tactile sensor is very weak in movements, efforts were made to maintain subject’s arm fixed, and 40Hz low pass filter was used to eliminate noise from power source and high frequency noise. Analyzing program was made to get time delay between first and second peak of averaged digital volume pulse(ΔTDVP), and subject’s height was divided by ΔTDVP to calculate stiffness index of arteries(SIDVP). Regression equations of systolic and diastolic pressure using SIDVP and mean arterial pressure(MAP) were computed from the training set(23 subjects) among total 46 subjects(age: 26.80±3.12, male: female = 32: 14) and were tested in 61 subjects to compensate error rate. Error rate in total subjects were systolic 6.51±9.25mmHg, diastolic 3.83±11.67mmHg, and those in the test setv were −5.50±9.27mmHg and 4.34±10.80mmHg each. Consequently, error rates were compensated especially in diastolic pressure using SIDVP, various slopes from digital volume pulse and MAP to systolic 2.57±8.05mmHg and diastolic 2.08±8.75mmHg.

This research intends to develop devices that make drivers rest and to verify in the early stage by effectively detecting the electrocardiogram (ECG) signal, one of the signals of living body, in the vehicle during the operation and providing ANS information and degree of stress. Recording the regular activity of heart clinically, ECG reflects the health state of subject as well as checks the degree of operation of autonomic nervous system through analysis of Heart Rate Variability (HRV). As this alteration of autonomic nervous system predicts the stress level of drivers during operation and provides the possibility of warning by continuous detection, it may lead to the recognition and safe driving of driver by detecting the stress during driving altered by diverse factors such as changing mood, bio rhythm, condition, fatigue, boredom or disease and preventing the driver from reaching the inappropriate state for driving. Thus, the reliability and utilization level of system was confirmed to be satisfactory by providing new ECG measuring method familiar to drivers and comparing it with the result of judging drivers' emotion through this research.

Although the results of venous occlusion plethysmography (VOP) can determine the existence of deep vein thrombosis (DVT), it is difficult to analyze quantitatively the effects of the degrees of thrombosis, blood pressure and cuff pressure on VOP. In this paper, by developing a combined model that is composed of a pulsatile cardiovascular model and a venous occlusion model, we showed the availability of a more realistic simulation. Using the proposed combined model for simulation of the effects of different head pressures and degrees of thrombosis on VOP, we can achieve a basic understanding of the relationship between the state of the patient and indirect measurements such as impedance plethysmography (IPG) and strain gauge plethysmography (SPG).

Presents a fractal interpolation compression method for ECGs. The method represents any range of ECG signal by fractal interpolation parameters. The variable range size technique is employed in order to reduce the reconstruction error. Small ranges are used for encoding rapidly varying parts of ECG to preserve the signal quality. The suggested algorithm was evaluated using MIT/BIH database. A high compression ratio is achieved with a relatively low percent rms difference. >

A new QRS detection algorithm using resonance theory is presented. After showing that the gradient of amplitude of ECG is proportional to frequency, we proposed an index function P which uses it as input. When it is equivalent to the value of the QRS characteristic frequency, the index function P returns to the very low value. Setting the detection threshold, we can finally detect QRS complexes. The new algorithm showed comparable or higher performance than other algorithms.

PURPOSE Photoplethysmography (PPG) is a noninvasive optical technology that detects changes in blood volume in the vascular system. This study aimed to investigate the possibilities of monitoring the cardiovascular system status by using PPG. MATERIALS AND METHODS Forced hemodynamic changes were induced using cardiac stimulants; dopamine and epinephrine, and PPG components were recorded by a noninvasive method at the peripheral blood vessels. The results were compared among 6 dogs. Endotracheal intubation was performed after an intramuscular injection of 25 mg/kg ketamine sulfate, and anesthesia was maintained with 2% enflurane. After stabilizing the animals for 15 min, 16 mg/mL diluted dopamine was injected into a vein for 2 min at 20 microg/kg min(-1) by using an infusion pump. Thereafter, the infusion pump was stopped, and 1 mg epinephrine was injected intravenously. Fluid administration was controlled to minimize preload change in blood pressure. RESULTS After stimulant administration, systolic blood pressure (SBP) and diastolic blood pressures (DBP) increased. The direct current (DC) component, which reflects changes in blood volume, decreased while the alternating current (AC) component, which reflects changes in vascular compliance and resistance, increased. The correlation coefficient between SBP and the foot of the DC component was 0.939 (p < 0.01), while it was 0.942 (p < 0.01) for DBP and the peak of the DC component. The AC component could predict the increase in vascular resistance from a stable pulse blood volume, even with increased pulse pressure. CONCLUSION These results support the possibility that PPG components may be used for easy and noninvasive measurement of hemodynamic changes in the cardiovascular system.