Quantification of fragmented QRS complex using intrinsic time-scale decomposition

http://dspace.vgtu.lt/bitstream/1/1795/1/2298_Bartkiene_%20Disertacija_WEB.pdf

Intelektualaus darbo našumo valdymas taikant biometrines technologijas

The invention relates to an electroencephalogram signal amplifying device and method. The device comprises an input buffer module, a notch module, a band-pass filter module, a common-mode rejection module and a differential amplification module. The input buffer module is used for collecting and outputting the original EEG signal. The notch module is used for filtering the power frequency interference signal of the original EEG signal and outputting the EEG notch signal; The band-pass filter module is used for filtering the high-frequency interference signal in the EEG notch signal and outputting the EEG filter signal. The common-mode rejection module is used for canceling common-mode interference of the original EEG signal and outputting the common-mode EEG signal. The differential amplification module is used for differentially amplifying the EEG filtered signal and the EEG common mode signal, and outputting the EEG amplified signal. The device and method solve the problems that theaccuracy of EEG signal acquisition is greatly affected by the introduction of various interference signals in the wire transmission process, and the input impedance of the acquisition system is not enough to collect the complete EEG signal.

An electroencephalogram signal amplifying device and method

The invention discloses an elastic collision demonstration device for physics teaching. The device comprises a column, a main shaft, a suspender bearing sleeve, a collision ball body, a rod bearing sleeve, a reaction rod body, a sleeve, a limit concave ring, a spring washer, a connecting piece, a tie bar, a reset spring, a mounting frame, a locking piece, a fixing clamping member, an upper end plate, a lower end plate, a locking bolt, a clamping groove and a suspender. The device is advantaged in that the device is convenient to use, is convenient to carry and is quite convenient to observe, determinants of the rotational inertia and influence on rotation of a rigid body can be directly shown through demonstration, angular momentum and rotational kinetic energy are indirectly reflected, the conservation law is verified, these concepts are gradually clarified, the relevant laws are correctly understood, phenomena are obvious, conclusion is intuitive, students are facilitated to think independently, the learning atmosphere is lively and lively, moreover, the device is simple and convenient to install, the device can be simply fixed at an edge of a table, the area of an experimental bench is greatly reduced, and other experimental items are convenient to dispose.

Elastic collision demonstration device for physics teaching

With the continuous development of wearable health monitoring technology, new types of Electrocardiogram (ECG) electrodes become the focus of attention, such as textile electrode, non-contact electrode, and micro-needle electrode. However, there are not yet unified performance testing methods for different types of electrodes. Two evaluating indicators proposed in the national pharmaceutical industry standard YY/T 0196-2005 (disposable ECG electrodes) are DC offset voltage and AC impedance. In this paper, Millipore films were used to simulate the human skin, and a testing platform for quantitatively evaluating the electrode performance was designed, composed of three parts: a simulating skin module, a pressure controlling device and a measuring device, which could simulate the electrochemical performance of the interface between ECG signals and human skin surface. And some quantitatively parameters, obtained with this platform, were impedance spectrum of electrode-skin contact interface, static open circuit voltage and dynamic open circuit voltage, which was very important for ECG electrode performance analysis. Keywords-wearable; electrode; millipore film; offset voltage; AC impedance

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A Performance Testing Platform of ECG Electrodes Based on Millipore Films

Electrocardiogram (ECG) is a noninvasive, economic, and convenient detecting tool in myocardial ischemia (MI), and its clinical appearance is mainly exhibited by ST-T complex changes. Recently, QRS complex characters in detecting MI were proposed by an increasing number of researchers. In this paper, various QRS complex characters were extracted in ECG, and their relationship was analyzed systematically. As a result, these characters were divided into two groups, and there was good correlation among them in each group, while the correlation between the groups was poor. Finally, these QRS complex characters were applied to myocardial ischemia, and five characters had significant differences after 59 normal ECG recordings verification, which were: QRS upward and downward slopes, transient heart rate, angle R and angle Q in a triangle QRS. Experimental results showed it was apparent that the trend changes of these five characters when MI events occurred were consistent with their relationship. The conduction velocity of action potentials in ventricular depolarization is slower in MI states than in normal states.

Relationship among qrs complex characters in electrocardiogram and its application to myocardial ischemia

The invention discloses a wearable electro-cardio signal collection device based on a fabric electrode. The device can carry out complete collection of electro-cardio signals of a human body aiming at the fabric electrode which is a novel flexible electrode. The device is characterized in that input impedance conversion of the fabric electrode could be achieved by an impedance conversion circuit, so the problem about high input impedance of the fabric electrode could be solved; common mode rejection and differential amplification are completed by a low-pass filtering circuit and a differential circuit; and finally, AD sampling and data set package transmission could be achieved. In comparison with a traditional electro-cardio collection circuit, the device disclosed by the invention is characterized in that the impedance conversion circuit is added at the fabric electrode part; power is supplied by a single power source; and an operational amplifier with a high signal to noise ratio and high input impedance is selected. In this way, the puzzle that signals are incomplete when the traditional electro-cardio collection circuits are used to extract the electro-cardio signals of the human body with application of the fabric electrode could be solved. The device is characterized by good performance, the small size and low power consumption. The device can be widely applied to wearable electro-cardio signal collection based on the fabric electrode; and comfort and convenience of use are enhanced.

Wearable electro-cardio signal collection device based on fabric electrode

The utility model includes a sphere pendulum bumping device suitable for a space environment. The device includes a first sphere, a second sphere, a transversal rod, a transversal rod bolt, a vertical rod, a pedestal, a connecting rod, a trifurcate connecting rod, a first steel ring, two second steel rings, a first rotating bearing and two second rotating bearings. One end of the connecting rod is fixedly connected to the first steel ring. The first steel ring is connected to one end of the transversal rod through the first rotating bearing and rotates round the transversal rod through the first rotating bearing. Two ends of the trifurcate connecting rod are respectively connected to the two second steel rings. Each second steel ring is connected to one end of the transversal rod through each second rotating bearing and rotates round the transversal rod through each second rotating bearing. The first steel ring is arranged at a central position between the two second steel rings. By employing the technical scheme of the utility model, the sphere pendulum bumping device can be used for demonstrating an experiment of momentum conservation law of a sphere pendulum bumping process in a weightless environment of the space environment.

Sphere pendulum bumping device suitable for space environment

This paper specifically distinguishes between external load and interior load and points out the relationship among external load, interior load, and fatigue. Rest-workload alternating pattern is designed as the external load to seek the adapting changes of heart rate (HR). When fatigue level is increasing, the RR intervals decrease (i.e., HR increases) under physical load, which shows the weakened capability of physical reaction to stress. The linear correlation between external load strength and interior load index RR interval is strong, i.e., RR intervals decrease (i.e., HR increases), when external load strength increases.

Chen Hua

Papers

Relationship among qrs complex characters in electrocardiogram and its application to myocardial ischemia

Wearable electro-cardio signal collection device based on fabric electrode

Sphere pendulum bumping device suitable for space environment

Heart Rate Changes Induced by Rest-Workload Alternating Pattern