OBJECTIVETo study the efficiency of electrocardiogram (ECG) monitor for positioning the catheter tip in the placement of peripherally inserted central catheter (PICC) in neonates.

METHODSA total of 160 neonates who were admitted to the neonatal intensive care unit (NICU) from January 2015 to December 2017 and underwent the PICC placement via the veins of upper extremity were enrolled. They were randomly divided into an observation group and a control group, with 80 neonates in each group. The neonates in the control group were given body surface measurement and postoperative X-ray localization, while those in the observation group were given body surface measurement, ECG localization, and postoperative X-ray localization. The two groups were compared in terms of general information, one-time success rate of PICC placement, and time spent on PICC placement.

RESULTSThere were no significant differences between the two groups in sex composition, gestational age, age in days at the time of PICC placement, disease type, and site of puncture (P>0.05). Compared with the control group, the observation group had a significantly higher one-time success rate of PICC placement (95% vs 79%; P<0.05) and a significantly shorter time spent on PICC placement (P<0.05). Localization under an ECG monitor during PICC placement had a sensitivity of 97% and a specificity of 100%.

CONCLUSIONSDuring the PICC placement in neonates, the use of ECG monitor to determine the position of catheter tip can improve the one-time success rate of placement and reduce the time spent on placement.

Catheterization, Central Venous ; instrumentation ; Catheterization, Peripheral ; methods ; Catheters, Indwelling ; Electrocardiography ; instrumentation ; Female ; Humans ; Infant, Newborn ; Male

PURPOSE: The mechanisms underlying syncope remain unknown in about 20% of patients with recurrent syncope. The implantable loop recorder (ILR) has been shown to be a useful diagnostic tool in patients with unexplained syncope even after negative initial evaluations. Nevertheless, ILR has rarely been used in clinical practice. MATERIALS AND METHODS: This study included 18 consecutive patients who had an ILR implanted at our center because of recurrent unexplained syncope after extensive diagnostic tests between February 2006 and June 2011. RESULTS: Diagnosis was confirmed in 10 (55.6%) of the 18 enrolled patients (13 males, 61+/-15 years). The confirmed diagnoses included sick sinus syndrome (n=6, 60%), advanced atrioventricular block (n=2, 20%) and ventricular tachyarrhythmia (n=2, 20%). The mean follow-up durations of the total study subjects and the diagnosed patients were 11.3+/-10.6 months and 5.6+/-9.2 months, respectively. Of the 10 diagnosed patients, 8 (80%) were diagnosed within 6 months of loop recorder implantation. CONCLUSION: ILR may be a valuable and effective diagnostic tool for patients with unexplained syncope.
Adult ; Aged ; Electrocardiography/instrumentation/methods ; Female ; Humans ; Male ; Middle Aged ; Monitoring, Physiologic/instrumentation/methods ; Syncope/*diagnosis/etiology

Non-contact measurement is an effective method of long time measurement of human electrocardiograph (ECG) signal. Because the relative position between measuring electrode and human body is not fixed, this method could result in constant changes of ECG signal collection. It often appears ECG signal distorting and weakened in filtering. This paper, using the principal component analysis (PCA) basic theory, proposes a fast adaptive PCA denoising algorithm which can automatically adjust the parameters according to the changes of ECG signal. The experiment proved that PCA denoising could be barely impacted by signal changes and can disposably remove interference signal on the premise of keeping the main features of ECG signal and can prevent ECG signal from being weakened in filtering at the same time.
Algorithms ; Artifacts ; Electrocardiography ; methods ; Humans ; Principal Component Analysis ; Signal Processing, Computer-Assisted ; instrumentation

To investigate the modulation effects of breathing movement on cardiovascular system and to study the physiological coupling relationship between respiration and cardiovascular system, we designed a comprehensive testing system for cardiorespiratory interaction research. This system, comprising three parts, i. e. physiological signal conditioning unit, data acquisition and USB medical isolation unit, and a PC based program, can acquire multiple physiological data such as respiratory flow, rib cage and abdomen movement, electrocardiograph, artery pulse wave, cardiac sounds, skin temperature, and electromyography simultaneously under certain experimental protocols. Furthermore this system can be used in research on short-term cardiovascular variability by paced breathing. Preliminary experiments showed that this system could accurately record rib cage and abdomen movement under very low breathing rate, using respiratory inductive plethysmography to acquire respiration signal in direct-current coupling mode. After calibration, this system can be used to estimate ventilation non-intrusively and correctly. The PC based program can generate audio and visual biofeedback signal, and guide the volunteers to perform a slow and regular breathing. An experiment on healthy volunteers showed that this system was able to guide the volunteers to do slow breathing effectively and simultaneously record multiple physiological data during the experiments. Signal processing techniques were used for off-line data analysis, such as non-invasive ventilation calibration, QRS complex wave detection, and respiratory sinus arrhythmia and pulse wave transit time calculation. The experiment result showed that the modulation effect on RR interval, respiratory sinus arrhythmia (RSA), pulse wave transit time (PWTT) by respiration would get stronger with the going of the slow and regular breathing.
Algorithms ; Artifacts ; Autonomic Nervous System ; physiopathology ; Diagnosis, Computer-Assisted ; methods ; Electrocardiography ; Equipment Design ; Heart ; physiology ; Humans ; Lung ; physiology ; Monitoring, Physiologic ; instrumentation ; methods ; Respiration ; Respiratory Mechanics ; physiology

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

Parsed the ECG descriptions in DICOM 3.0 standard and accomplished a DICOM-ECG file which conforms to the DICOM standard by a toolkit DCMTK. The DICOM-ECG file can communicate with systems which support DICOM standard directly.
Electrocardiography ; instrumentation ; methods ; Information Storage and Retrieval ; Software

The high-pass filter which is designed to overcome the polarization voltage in the ECG measurements can affect the measurement of the ST-segment; but the accuracy of the ST-segment will have an impact on the diagnosis and treatment of heart diseases. This paper used the ECG detection platform to test the effect of the high-pass filter at different frequency and studied the effect of the high-pass filter on the ST segment to ensure proper use of different application modes.
Electrocardiography ; instrumentation ; methods ; Filtration

This study designed an audio signal acquisition system to achieve real-time detection of R peak for heart rate variability (HRV) analysis, substituting ECG-specific data acquisition board with sound card. It is proved that the R peak with low frequency can be gathered by sound card. The comparison with PowerLab signal acquisition system has shown that the acquisition system of R peak could accurately detect the R peak. The R peak detected by sound card and PowerLab signal acquisition system completely overlap each other, while RR intervals has no difference. The HRV analysis was accurate and reliable with the RR interval from sound card. This low cost, high performance, strong compatibility and easy upgraded acquisition system of R peak compared with the traditional data acquisition board has the value of practical uses and might have broad applications in the future.
Algorithms ; Electrocardiography ; methods ; Heart Rate ; physiology ; Humans ; Monitoring, Physiologic ; instrumentation ; Signal Processing, Computer-Assisted ; instrumentation ; Sound

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

Using 49 capacitive-coupled electrodes, mattress-type harness was developed to obtain posterior body surface potential map (P-BSPM) in dressed individuals. The aim of this study was to investigate how valuable information P-BSPM could provide, especially in discrimination of old myocardial infarction (OMI). P-BSPM of 59 individuals were analyzed; 23 normal control, 11 right bundle branch block (RBBB), 3 left bundle branch block (LBBB) and 19 OMI patients. Principal component analysis and linear hyper-plane approach were used to evaluate diagnostic performance. The axes of P-BSPM vector potential corresponded well with 12-lead electrocardiogram. During QRS, the end point of P-BSPM vector potential demonstrated characteristic clockwise rotation in RBBB, and counterclockwise rotation in LBBB patients. In OMI, initial negativity on P-BSPM during QRS was more frequently located at lower half, and also stronger in patients with inferior myocardial infarction (MI). The area under the receiver-operating characteristic curve of P-BSPM during QRS in diagnosing overall OMI, anterior MI, and inferior MI was 0.83 (95% confidence interval, 0.70-0.97), 0.71 (0.47-0.94), and 0.98 (0.94-1.0), respectively (P = 0.022 for anterior vs inferior MI groups). In conclusion, the novel P-BSPM provides detailed information for cardiac electrical dynamics and is applicable to diagnosing OMI, especially inferior myocardial infarction.
Adult ; Aged ; Area Under Curve ; Body Surface Potential Mapping/instrumentation/*methods ; Bundle-Branch Block/diagnosis ; Electrocardiography ; Electrodes ; Humans ; Male ; Middle Aged ; Myocardial Infarction/diagnosis ; Principal Component Analysis ; ROC Curve