[Miniature Wireless ECG Sensor for Mobile Medical Treatment].

A kind of miniature wireless ECG sensor is designed for mobile medicine in the paper.The miniature wireless ECG sensor acquires ECG signals of human body by single lead,and it transmits the processed ECG data to mobile phone through Bluetooth transmission technology to realize ECG waveform,heart rate display and ECG data storage.The wireless ECG sensor has the advantages of simple operation,high accuracy,strong anti-interference ability and good real-time performance.It can monitor some arrhythmia and other diseases for a long time.

[Time-frequency Research of Pulse Rate Variability Based on the EEMD].

In this paper, based on the feature of ensemble empirical mode decomposition(EEMD) which is very suitable for analyzing non-stationary and nonlinear signals, the pulse rate variability (PRV) signal is decomposed into multiple intrinsic mode function (IMF) components by EEMD, to calculate the energy of each IMF component respectively, and high-frequency energy(EHF), low-frequency energy(ELF) and very low-frequency energy(EVLF) of PRV were reconstructed from the energy of the IMF components according to the characteristics of each IMF component spectrum. This method is compared with the traditional AR power spectrum estimation method through the experiment. The results show that the correlation coefficient of each frequency domain parameter corresponding to PRV obtained by the two methods is higher than 0.96, which indicates that the method can truly reflect the sympathetic nerve and vagus nerve activity.

[A new method for calculating pulse oxygen saturation].

Real-time updates of metrical data can not generally be realized in the commonly used methods for calculating the pulse wave of blood oxygen saturation. Based on the hardware platform of pulse wave signal from NJL5501 R, and high linear correlation of the red laser and infrared light collected in pulse wave signal measurement, an approach to determine the value of the blood oxygen saturation is proposed in the present paper by establishing the linear regression model of the red laser and infrared light. The effect of the sampling number of pulse wave signal in calculation on the characteristic parameters of pulse wave is also analyzed. The experimental results showed that the approach could guarantee the measuring accuracy and realize the fast updates of blood oxygen saturation data. This paper provides an effective method for real-time and accurate monitoring of pulse blood oxygen saturation in human body.

[Wireless Passive Body Sensor for Temperature Monitoring Using Near Field Communication Technology].

In this study, we designed a wireless body temperature sensor (WBTS) based on near field communication (NFC) technology. Just attaching the WBTS to a mobile phone with NFC function, the real-time body temperature of human subjects can be acquired by an application program without seperate power supply. The WBTS is mainly composed of a digital body temperature probe (d-BTP), a NFC unit and an antenna. The d-BTP acquires and processes body temperature data through a micro control er, and the NFC unit and antenna are used for wireless energy transmission and data communication between the mobile phone and WBTS. UART communication protocol is used in the communication between the d-BTP and NFC unit, and data compression technique is adopted for improving transmission efficiency and decreasing power loss. In tests, the error of WBTS is ±0.1 oC, in range of 32 oC to 42 oC. The WBTS has advantages of high accuracy, low power loss, strong anti-interference ability, dispensation with independent power supply etc., and it can be integrated into wearable apparatuses for temperature monitoring and health management.

[A USB-Based Digital ECG Sensor].

Based on the ECG-specific BMD 101 integrated circun chip, this study designed a digital ECG sensor. In practical application, users just need to connect the ECG sensor 'o upper computer (such as PC or mobile phone) through USB interface, to realize the functions including display, alarm, saving, transfer etc. After tests, They demonstrate that the sensor can be applied to the detection of arrhythmia, such as bigeminy coupled rhythm, proiosystole etc. Besides, the sensor has various advantages in monitoring an managing the heart health of people out of hospital, including low cost, small volume, usableness, simplicity of operation etc.

[A Wearable Wireless Body Sensor for Epileptic Seizure Prediction].

In this study, we designed a wearable patch-type ECG sensor (WPES), which is mainly composed of the electrodes, an ECG acquisition unit, a Bluetooth unit, and a power supplies module. By using BMD101 chip as the core of ECG acquisition, the WPES can communicate with smart phones through Bluetooth low energy (BLE). The WEPS can be well used in monitoring epileptic seizure prediction, based on the advantages of simplification of circuits, miniaturization, low-power consumption, light-weight, convenience of wearing, high-comfort etc.

[A Heart Rate Variability Analysis System for Short-term Applications].

In this paper, a heart rate variability analysis system is presented for short-term (5 min) applications, which is composed of an electrocardiogram signal acquisition unit and a heart rate variability analysis unit. The electrocardiogram signal acquisition unit adopts various digital technologies, including the low-gain amplifier, the high-resolution analog-digital converter, the real-time digital filter and wireless transmission etc. Meanwhile, it has the advantages of strong anti-interference capacity, small size, light weight, and good portability. The heart rate variability analysis unit is used to complete the R-wave detection and the analyses of time domain, frequency domain and nonlinear indexes, based on the Matlab Toolbox. The preliminary experiments demonstrated that the system was reliable, and could be applied to the heart rate variability analysis at resting, motion states etc.

[Filtering method of power frequency interference in ECG signals].

Electrocardiogram (ECG) signals are susceptible to be disturbed by 50 Hz power frequency in the process of acquisition and conversion. This paper puts forward the improved Levkov algorithm combined with the antisymmetry of sine wave and the characteristic of not--easily mutation of the sine wave amplitude. The improved and the original algorithms were compared with signal to noise ratio (SNR), root mean square error (RMSE) and coincidence of the signals. Based on the experimental comparison, it was concluded that the improved algorithm had better filte-ring functions, because it not only highly coincided with ECG, but also retained certain details of ECG.

[Continuous ECG recording for freely moving patients].

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.

[The design of handheld fast ECG detector].

A new handheld fast ECG detector based on low gain amplifier, the high resolution analog to digital converter, the real-time digital filter, fast P-QRS-T wave detection and abstraction algorithm was designed. The results showed that the ECG detector can meet the requirements of fast detecting heart rate and ECG P-QRS-T waveforms.