Measured ECG Signals Research Articles

Evaluation of a Behind-the-Ear ECG Device for Smartphone Based Integrated Multiple Smart Sensor System in Health Applications

In this paper, we present a wireless Multiple Smart Sensor System (MSSS) in conjunction with a smartphone to enable an unobtrusive monitoring of electrocardiogram (ear-lead ECG) integrated with multiple sensor system which includes core body temperature and blood oxygen saturation (SpO2) for ambulatory patients. The proposed behind-the-ear device makes the system desirable to measure ECG data: technically less complex, physically attached to non-hair regions, hence more suitable for long term use, and user friendly as no need to undress the top garment. The proposed smart sensor device is similar to the hearing aid device and is wirelessly connected to a smartphone for physiological data transmission and displaying. This device not only gives access to the core temperature and ECG from the ear, but also the device can be controlled (removed and reapplied) by the patient at any time, thus increasing the usability of personal healthcare applications. A number of combination ECG electrodes, which are based on the area of the electrode and dry/non-dry nature of the surface of the electrodes are tested at various locations near behind the ear. The best ECG electrode is then chosen based on the Signal-to-Noise Ratio (SNR) of the measured ECG signals. These electrodes showed acceptable SNR ratio of ~20 db, which is comparable with existing tradition ECG electrodes. The developed ECG electrode systems is then integrated with commercially available PPG sensor (Amperor pulse oximeter) and core body temperature sensor (MLX90614) using a specialized micro controller (Arduino UNO) and the results monitored using a newly developed smartphone (android) application.

헬스케어 가방의 ECG 센서 전극 위치에 따른 신호 분석

Heart rate is one of the most important signal to monitor the health condition of the patient or exerciser. Various wearable devices have been developed for the continuous monitoring of ECG signal from human body during exercise. Among these, ECG chest belt has been widely used. However wearing chest belt with ECG sensor is uncomfortable in normal life due to the electrode contact between metal electrodes of ECG sensor and skin of the human body. So we develop the royal healthcare backpack that can measure ECG signal without skin contact by using capacitor-type ECG sensor. The position of the measurement point is critical to collect a clear ECG signal in the capacitive ECG measurement from backpack. Various tests were conducted to find the optimal ECG measurement position which has less noise and could get strong and clear ECG signal during exercise, walking, hiking, mountain climbing and cycling.

Healthcare Measurement of ECG and Body Temperature Signals Using Android Mobile

This project is a step towards the preventative healthcare for cardiac patients. It seeks to develop a smart mobile ECG monitoring system that continuously monitors what is happening around the subject when an arrhythmia event occurs. The problem we are facing now is the unexpected death of our loved ones because of the sudden heart attack. Because of the changing life style the heart attack rate is increasing day by day. The current heart attack death rate is about 25% of the total deaths in India. The main cause of heart attack death is the lack of medical care at the right time. This problem can be avoided by this project. Here I am presenting an android based portable ECG monitor. The patient will be wearing a small device which senses the ECG data. It will send the sensed data to the patient’s Android mobile through Bluetooth. The Android mobile will be having an application which will be running a heart attack detection algorithm. If any abnormalities are found the patient will be notified through an audible alarm and first aid techniques will be shown to the patient in the phone’s display. This first aid instruction will increase the chance of survival of the patient. A report of the ECG will be send to the patient’s doctor through email so that he can prepare himself for the treatment. And also a sms containing patient’s location (gps data) will be send to the hospital so that help can be given at the earliest even if the patient is travelling. The goal is to provide early heart attack detection so that the patient will be given medical attention within the first few critical hours, thus greatly improving his or her chances of survival.

An ECG Compressed Sensing Method of Low Power Body Area Network

Aimed at low power problem in body area network, an ECG compressed sensing method of low power body area network based on the compressed sensing theory was proposed. Random binary matrices were used as the sensing matrix to measure ECG signals on the sensor nodes. After measured value is transmitted to remote monitoring center, ECG signal sparse representation under the discrete cosine transform and block sparse Bayesian learning reconstruction algorithm is used to reconstruct the ECG signals. The simulation results show that the 30% of overall signal can get reconstruction signal which’s SNR is more than 60dB, each numbers in each rank of sensing matrix can be controlled below 5, which reduces the power of sensor node sampling, calculation and transmission. The method has the advantages of low power, high accuracy of signal reconstruction and easy to hardware implementation. DOI : http://dx.doi.org/10.11591/telkomnika.v12i1.3995

A Design of EMD-based Filter to Remove Motion artifacts in Wireless ECG Monitoring

Motion artifact distorted ECG signal is a commonly known issue in mobile ECG recording. In this paper, we present a better method to replace existing filtering technique while preserving distortion free ECG signal. A belt-type ECG measurement system to measure ECG signal in daily life has been developed. A 3-axis accelerometer sensor is installed on the ECG measurement system to obtain activity data. Activity status is classified using fuzzy rule base classifier. Then an optimal adaptive filter using empirical mode decomposition, EMD is proposed for motion artifact removal. EMD is used to decompose motion artifact from the ECG signal and finally preserve a distortion free ECG signal at the end of the result.

심박 및 심박변화를 통한 최대 지방 연소 시점의 추정

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<0.01 with 0.950, respectively. Furthermore, in the changes in LF & HF, we have determined the point where the normalized area value starts to become the same as the maximal fat oxidation point, and the correlation here showed 0.620 in Kendall and 0.780 in Spearma of which both showed significant results as p＜0.01.

First clinical evaluation of a novel capacitive ECG system in patients with acute myocardial infarction

ObjectiveThe ECG plays a central role in the rapid diagnosis of acute myocardial infarctions (MI). In haemodynamically instable patients, adhesion of electrodes sometimes is difficult and assessing ECGs through layers of clothes has not been done so far. A novel capacitive measurement of ECG signals is possible without skin contact. Whether this technical innovation can be used in patients with MI is unclear.MethodsWe evaluated a capacitive ECG system (cECG) in patients with anterior and inferior ST elevation MI (STEMI) as compared to patients without ST elevations in anterior and inferior leads. The cECG was assessed using a sensor array consisting of 15 electrodes of which the classical leads I, II, III, aVL, aVF and V1–V3 were calculated from. 66 patients were included in the study. In addition to the conventional ECG (kECG) the novel cECG was registered before reperfusion therapy was started.ResultsIn a first round, 19 patients presented with anterior MI, 23 with inferior MI, and 7 either with left bundle branch block or lateral MI. Regarding anterior MI, a significant correlation (P < 0.05) was found between ST elevations in leads I, aVL, V2 and V3 comparing cECG and kECG. In inferior MI, there was only a significant correlation (P < 0.05) in lead III between cECG and kECG, but not in II and aVF. Therefore, 17 additional patients were included in the study by placing an additional electrode further away from the sensor array on the chest. ST elevations now correlated in all inferior leads II, III and aVF (P < 0.05) as measured in 9 patients with inferior MI. In addition, in 8 patients an inferior MI was correctly ruled out.ConclusionIt is possible to identify STEMIs by cECG. This innovative technique could play an important role in the pre-hospital period as well as in the hospital.

Variable Threshold Method for ECG R-peak Detection

In this paper, a wearable belt-type ECG electrode worn around the chest by measuring the real-time ECG is produced in order to minimize the inconvenient in wearing. ECG signal is detected using a potential instrument system. The measured ECG signal is transmits via an ultra low power consumption wireless data communications unit to personal computer using Zigbee-compatible wireless sensor node. ECG signals carry a lot of clinical information for a cardiologist especially the R-peak detection in ECG. R-peak detection generally uses the threshold value which is fixed. There will be errors in peak detection when the baseline changes due to motion artifacts and signal size changes. Preprocessing process which includes differentiation process and Hilbert transform is used as signal preprocessing algorithm. Thereafter, variable threshold method is used to detect the R-peak which is more accurate and efficient than fixed threshold value method. R-peak detection using MIT-BIH databases and Long Term Real-Time ECG is performed in this research in order to evaluate the performance analysis.

휴대용 심전도 기기와 직물형 전극을 이용한 생체정보 측정용 밀착 의복 개발

A Holter monitor is used for ECG monitoring of ambulatory daily life in hospital. However, the use of this apparatus causes skin allergies and discomfort in patients because of the attachment gel and tapes used to attach disposable electrodes to the skin. In this study, the development of tight-fitting clothing connected to a portable Holter monitor was proposed. In addition, the use of conductive fabrics as electrodes was proposed; this will enable the use of garments in u-health care for measuring ECG signals. The male subjects were university students in the ages of 20 to 24. Subjective wear sensations of the experimental garments were rated using seven Likert scales. A Likert type scale was used for the evaluation and a 7 point score indicates that it provided the best fit as a tight-fitting upper clothing. Clothing pressure was measured using an air-pack-type pressure sensor (model AMI 3037-2) at 4 locations (the conductive fabric electrode) As results, a male basic sloper for upper clothing was developed and that pattern was manipulated to the tight fit pattern by considering the reduction rate of the percentage stretch in the fabric. The developed tight-fitting garment was superior in terms of subjective sensation and 6t. The mean pressure of the garment with reduction rates of 40% in width and of 50% in length was 8.45gf/. A conductive fabric electrode was developed by considering the sewing method and the developed electrode was detected well. The ECG data were recorded for 13 hr 19 min 44 sec and the artifacts in the ECG signals were recorded for 9 hr 3 min 46 sec (total time: 22 hr 23 min 23 sec). The artifacts data were obtained during heavy activities.

일상생활 중 건강모니터링을 위한 착용형 심전도계측 시스템 개발

In this study, wearable ECG measurement system was implemented for health monitoring during daily life. A wearable belt-type ECG electrode worn around the chest by measuring the real-time ECG is produced in order to minimize the inconvenience in wearing. The measured ECG signal is transmitted via an ultra low power consumption wireless data communications unit to personal computer using Zigbee-compatible wireless sensor node. The ECG monitoring program is developed at end user which is personal computer. The measured ECG contains many noises mainly due to motion artifacts. For ECG signal processing, adaptive filtering process is proposed which can reduce motion artifacts efficiently and accurately than digital filter. The experimental results show that a reliable performance with high quality ECG signal can be achieved using this wearable ECG monitoring system.

Non-invasive model-based localization of ventricular ectopic centers from multichannel ECG

Non-invasive localization of premature ventricular beat (PVB) foci is very important for medical treatment of numerous cardiac diseases. In this work a model-based method of reconstruction of ectopic center locations is investigated. Within the scope of this method patient's multichannel ECG is used as a reference for optimization of an electrophysiological cardiac model. This model is based on the cellular automaton principle and utilizes anatomical data of the patient. Optimized are coordinates of the ectopic focus as well as excitation conduction velocity of ventricular myocardium. Initial values for these parameters are obtained by solving the linearized problem of electrocardiography in terms of activation times. Optimization is performed by minimization of discrepancy between the simulated and reference ECGs. The aim of the current work is to estimate the quality of ectopic focus localization delivered by this method. Four sample ectopic beats have been simulated, with their foci located in different regions of the left ventricle. 1% Gaussian noise has been introduced into the resulting ECGs. In this way the measured ECG signals for this investigation have been obtained. Afterwards the origin of each ectopic beat has been reconstructed using the model-based approach. The method has demonstrated reliable localization of PVB foci, reconstruction errors have not exceeded 6.1 mm.

실시간 심전도 분석 및 모니터링 시스템 개발

ECG is used on purpose to keep good health or monitor cardiac function of aged person as well as on purpose to diagnose the disease of heart patients. The ambulatory ECG monitoring system under guarantee of safety and accuracy is very efficient to prevent the progress of heart disease and sudden death. These systems can detect the temporary change of ECG that is very significant to diagnose heart disease such as myocardial ischemia, arrhyamia and cardiac infarction. In this paper, we describe the ECG signal analysis algorithm and measurement device for ECG monitoring. The authors designed a small-size portable ECG device that consisted of instrumentation amplifier, micro-controller, filter and RF module. The device measures ECG with four electrodes on the body and detects QRS complex and ST level change in realtime. Also it transmits the measured signals to the personal computer. The developed software for ECG analysis in personal computer has the function to detect the feature points and ST level changes.

A novel fully integrated device dedicated to ECG signal measurement

This paper describes two novel fully integrated circuits implemented in standard 0.35 μm CMOS technology dedicated to ECG signal measurement. Many specific problems related to this kind of signal are discussed. Pertinent solutions, such as high pass filtering, offset cancellation, common mode rejection, low pass filtering and capacitive coupling between different stages are proposed.

Wireless Transmission of ECG signal

In this study, the ECG signal were measured as noiseless with Ag/AgCl electrodes, then converted digital data using pulse code modulation (PCM) technique. The digital data were then sent to receiver where it is in 433 MHz FM/FSK transmitter, which has 10 mW output power and 9.6 Kps transmission speed. At the receiver, the digital data were reconverted to analog signal to monitor and record on the PC with Sonic Foundry Sound Forge 6.0 program. The power spectrum of measured ECG signal was formed using Matlab program. As a result, the medical supporting system is realized for monitoring the ECG signal on PC of human with chronic heart disease in their living surroundings.

Autocorrelation function analysis of ECG signals in 20 rabbits.

In this experiment, we measured ECG signals of lead I, respectively, during normal and arrhythmia after 20 rabbits were anaesthetized. These signals were recorded, then the information was put into a computer and it analyzed Autocorrelation (AC) Function, and Power Spectrum. The results make us know: (1) periodicity corresponding relationship of ECG in normal rabbits can derive reflects from changes of ECG AC function changes of ECG signals in arrhythmia rabbits can derive relatively sensitive reflection from changes of ECG function (attenuating area S and the value of k) in normal rabbits. (2) The Autocorrelation Function of Electrocardio change but ECG in the normal. All these provide another useful method for the diagnosis of arrhythmia.