A Heart Rate Variability Analysis System for Short-term Applications / 生物医学工程学杂志

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.

Analysis of Pulse Rate Variability and Its Application to Wearable Smart Devices / 中国医疗器械杂志

In this paper, a reflection type photoelectric pulse wave sensor was designed for short-term pulse rate variability analysis. Photoplethysmography (PPG) signals and ECG signals (obtained with the Dimetek MicroECG recorder Dicare-m1CP) were recorded synchronously from 20 healthy subjects. The analytical results show a significant correlation (correlation coefficient r > 0.99) between the PPG-derived peak-to-peak (PP) intervals and the ECG-derived RR intervals. Besides, there are no significant differences (P > 0.05) between the HRV measured by ECG and the PRV quantified by the PPG whether in time domain, frequency domain, or the Poincaré plot parameters. The experimental results suggest that the PPG-based short-term PRV analysis can be consistent with the ECG-based HRV measurement in wearable smart devices.

The design of handheld fast ECG detector / 中国医疗器械杂志

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.

Continuous ECG recording for freely moving patients / 生物医学工程学杂志

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.