Anti-motion artifact is one of the most important properties of ambulatory ECG monitoring equipment. At present, there is a lack of standardized means to test the performance of anti-motion artifact. ECG simulator and special conductive leather are used to build the simulator, it is used to simulate human skin, to generate ECG signal input for the ECG monitoring equipment attached to it. The mechanical arm and fixed support are used to build a motion simulation system to fix the conductive leather. The mechanical arm is programmed to simulate various motion states of the human body, so that the ECG monitoring equipment can produce corresponding motion artifacts. The collected ECG signals are read wirelessly, observed, analyzed and compared, and the anti-motion artifact performance of ECG monitoring equipment is evaluated. The test results show that by artificially creating the small difference between the two groups of ambulatory ECG monitoring equipment, the system can accurately test the interference signals introduced under the conditions of controlled movement such as tension and torsion, and compare the advantages and disadvantages. The research shows that the test system can provide convenient and accurate verification means for the research of optimizing anti-motion interference.
Humans ; Artifacts ; Signal Processing, Computer-Assisted ; Electrocardiography, Ambulatory/methods* ; Electrocardiography ; Motion

The amplifier is easy to saturation because of polarization voltage in ambulatory ECG acquisition. The traditional way is using analog high-pass filter to eliminate, but the output tends to have a residue. If upgrading high-pass filter cutoff frequency, it will lead to low frequency distortion of ECG signals. In this paper, a Savitzky-Golay (SG) smoothing filter has been designed by combining the single edge point and the polynomial order , which can fit the polarization voltage components of ECG signals, filter useful components and get drift-free ECG signals by using the subtraction algorithm. The results of ECG filtering experiment verify the feasibility of the SG smoothing filter, and show the filtered ECG signal without any losses of useful components.
Algorithms ; Amplifiers, Electronic ; Electrocardiography, Ambulatory ; methods ; Humans ; Signal Processing, Computer-Assisted

OBJECTIVE: That treatment with second-generation antipsychotics (SGAs) causes metabolic side effects and atherosclerosis in patients with schizophrenia and bipolar disorder (BD) is well-known. Increased arterial stiffness is an important marker of arteriosclerosis and has been identified as an independent risk factor for cardiovascular diseases. We measured pulse wave velocity (PWV) as a marker of arteriosclerosis in patients with schizophrenia and BD who use SGAs. METHODS: Patients and controls were collected from our psychiatry outpatient clinics or family medicine. Mental illness was diagnosed according to the Diagnostic and Statistical Manual of Mental Disorders, 4th edition. Mean age, gender, systolic and diastolic blood pressure, body mass index, Framingham risk score (FRS), etc. were determined. Simultaneous electrocardiography and pulse wave were recorded with an electromyography device. The photo-plethysmographic method was used to record the pulse wave. Inclusion criteria included use of SGAs for at least the last six months. Patients with diseases that are known to cause stiffness and the use of typical antipsychotics were excluded. RESULTS: Ninety-six subject (56 patients, 40 controls) were included in our study. There were 49 females, 47 males. Patients had schizophrenia (n=17) and BD (n=39). Their treatments were quetiapine (n=15), risperidone (n=13), olanzapine (n=15), and aripiprazole (n=13). Although differences in mean age, gender, and FRS in the patient and control groups were not statistically significant (p=1), PWV was greater in patients in the antipsychotic group (p=0.048). CONCLUSION: This study supported the liability to stiffness in patients with schizophrenia and BD. Using SGAs may contribute to arterial stiffness in these patients.
Ambulatory Care Facilities ; Antipsychotic Agents* ; Aripiprazole ; Arteriosclerosis ; Atherosclerosis ; Bipolar Disorder ; Blood Pressure ; Body Mass Index ; Cardiovascular Diseases ; Diagnostic and Statistical Manual of Mental Disorders ; Electrocardiography ; Electromyography ; Female ; Humans ; Male ; Methods ; Pulse Wave Analysis ; Quetiapine Fumarate ; Risk Factors ; Risperidone ; Schizophrenia ; Vascular Stiffness*

As more and more people are becoming aged in China and many of them tend to suffer from chronic cardiac problems, the long-term dynamic cardiac monitoring for freely moving patients becomes essential. A new design for continuous ECG recording on the freely moving patients at home and/or at work is proposed here. It is miniature in size, using digital technologies of the low gain amplifier, the high resolution analog to digital converter and the real-time digital filter that features > 100dB input signal dynamic range (ISDR), > 100dB common-mode rejection ratio (CMRR), and < 5microV (RMS) internal noise. The device works continuously more than 24 hours with a pair of AAA batteries, and is capable of storing the recorded data into a storage card. The preliminary tests showed that the P-QRS-T waveforms were captured and displayed smoothly in resting, walking, and activities, making the device useful in monitoring and analyzing for the patients on the move.
Electrocardiography, Ambulatory ; instrumentation ; methods ; Equipment Design ; Humans ; Signal Processing, Computer-Assisted ; Software

The principle of ambulatory cardiac output (CO) measuring technique is introduced in this paper. Experimental studies about the applicability of the two-compartment coaxial cylindrical model for ambulatory measurement of cardiac output with spot-electrodes have been carried out with using our newly-developed multi-channel impedance mapping system. The key factors using a spot-electrode array instead of a conventional band-electrode array for non-invasive CO) measurement are elaborated. The variations of the electric impedance pulsatile component (deltaZ waveform) and the two kinds of typical modes of deltaZ distributions measured by six electrodes on the midsternal (midian) line from the medial portion at the level of clavicle to the portion above the xiphisternum are discussed. The applicability of the two-compartment coaxial cylindrical model for ambulatory measurement of CO with spot-electrodes is analyzed. Synthesizing the deltaZ distributions and their typical changing models on the midsternal (midian) line during blood inflowing into aorta is the optimal positions of a pair of spot-electrodes for voltage pick-up at the level of clavicle for the upper electrode and the position at the level of nipple for the lower electrode when spot-electrode is being used to measure non-invasive CO.
Biomedical Engineering ; Cardiac Output ; physiology ; Cardiography, Impedance ; instrumentation ; methods ; Electrocardiography, Ambulatory ; instrumentation ; methods ; Electrodes ; Equipment Design ; Heart ; physiology ; Humans ; Models, Cardiovascular ; Thorax

INTRODUCTIONUnexplained syncope is a common condition with a significant impact both on the patient and on healthcare expenditure. Often, the diagnosis is hampered due to the temporary sporadic nature of the symptoms. Conventional monitoring methods have a low yield for identifying an abnormality during a spontaneous event. The implantable loop recorder (ILR), often underutilised, is an important diagnostic device that may fi ll this void in the early assessment of patients presenting with syncope.

MATERIALS AND METHODSThis article begins with 2 case vignettes which highlight the clinical utility of ILRs in making a definitive diagnosis and guiding subsequent management. This is followed by a review of the existing evidence for ILRs, including the recent international guidelines, underpinning the role of ILRs in the present management algorithm of patients presenting with unexplained syncope. The technical aspects and cost implications will also be reviewed.

RESULTSPresent evidence-based international guidelines have recommended the early use of ILRs in the management of patients with unexplained syncope. Furthermore, there may also be an important role for ILR use in patients with presumed epilepsy refractory to treatment and in the neurally mediated syncope cohort with recurrent symptoms. Cost benefit analysis also demonstrates advantages with early ILR use.

CONCLUSIONThe early use of ILR in selected patients remains an accurate, cost-effective, high yield tool for diagnosis and management of patients with unexplained syncope. However, its use should not detract from the importance of taking a detailed medical history and physical examination in the initial assessment to facilitate identification of the aetiology and risk stratification of patients.

Adult ; Aged ; Algorithms ; Arrhythmias, Cardiac ; complications ; diagnosis ; Cost-Benefit Analysis ; Electrocardiography, Ambulatory ; economics ; instrumentation ; methods ; Female ; Heart Arrest ; complications ; diagnosis ; Heart Diseases ; complications ; diagnosis ; Humans ; Syncope ; diagnosis ; etiology

Motion artifacts are a main interference source of ambulatory physiology signals. The interference in wearable detection systems is more serious because of using dry electrodes. On account of the instantaneity in motion artifacts and periodicity in physiological signal, we presented a new method based on periodic component analysis for motion artifact reduction. The single channel signal is transformed into multi-channel signal with multi resolution analysis, and then periodic component analysis can help us to separate the normal physiological signal from motion artifacts. A case study in electrocardiogram (ECG) demonstrates that periodic component analysis is better than the empirical mode decomposition and adaptive filtering methods. Periodic component analysis as a time domain method can discriminate the signal with frequency aliasing, and recover the ECG waveform feature corrupted. This method can be easily extended to other physiological signal processing.
Algorithms ; Ambulatory Care ; methods ; Artifacts ; Electrocardiography, Ambulatory ; methods ; Humans ; Monitoring, Physiologic ; methods ; Principal Component Analysis ; methods ; Signal Processing, Computer-Assisted

This paper proposes a method of automatic ECG analysis and arrhythmia diagnosis for telemonitoring system. A multi-buffer technique is applied to organize dispersive ECG data. Then, according to second order derivatives of ECG signals, peaks of R waves are automatically detected. Finally, real-time heart rhythm is decided by results of R wave detection. Tests prove that the proposed method is precise, efficient and stable to be applied in real-time ECG telemonitoring system.
Algorithms ; Automation ; instrumentation ; methods ; Electrocardiography, Ambulatory ; instrumentation ; methods ; Remote Consultation ; instrumentation ; methods ; Signal Processing, Computer-Assisted

In this paper is presented the Lorenz plot, the qualitative analyses and quantitative parameters of the plot. The long axis vs short axis(LVS) parameter is given. Atrial Fibrillation Electrocardiogram (AF ECG) is compared with sinus ECG by use of Lorenz plot. Then the difference in their plots and the parameter of LVS is pointed out. Lorenz plot finding is useful for the AF disease in automatic diagnoses of ECG signals.
Atrial Fibrillation ; diagnosis ; physiopathology ; Automatic Data Processing ; methods ; Electrocardiography, Ambulatory ; methods ; statistics & numerical data ; Heart Rate ; Humans ; Signal Processing, Computer-Assisted

In this paper, we introduce the design of an electrocardiogram (ECG) collecting circuit based on distance-wireless ECG monitor. The circuit not only amplifiers the ECG signal and filter, but also automatically detects lead-fall.
Electrocardiography, Ambulatory ; instrumentation ; methods ; Equipment Design ; Humans ; Monitoring, Ambulatory ; instrumentation ; methods ; Remote Consultation ; methods ; Signal Processing, Computer-Assisted ; Wireless Technology ; instrumentation