Personalia
Northeastern University——高汉(Han van Triest)   
Name:     Lisheng Xu
Department:     Sino-Dutch School for Biomedical and Information Engineering
Position:     Professor
Title:     Ph.D
Email address:     xuls@bmie.neu.edu.cn

Short Biography


Dr. Lisheng XU is the director of the biomedical electronics institute in Sino-Dutch Biomedical and Information Engineering School of Northeastern University, and he is also working as a professor at the Key Laboratory of Medical Image Computing of Ministry of Education, China. His main research areas include medical signal processing, cardiovascular system modeling, patter recognition, medical biometrics, electromagnetic bio-effects, biomedical electronics and wireless sensor networks. Currently Prof. Xu and his students are paying more attention to the comprehensive analysis of non-invasive cardiovascular images and signals to further disclose the mechanism of the occurrence and development of cardiovascular diseases.

Prof. Xu has a strong background of practical work on medical systems and system integration. The heart rate variability analysis module developed by Prof. Xu’s lab has been applied in the products of Neusoft Inc. (http://medical.neusoft.com/en/), which is well-known in China for producing healthcare equipment. Prof. Xu also gives some consult for Neusoft Inc. In addition, Prof. Xu has closely cooperated with the Chinese medical universities and hospitals. He is working as a professor in the Cardiovascular Study Center of Chinese Medical University, which is famous for its experimental conditions and advanced equipment.

Prof. Xu has authored or coauthored more than 171 international research papers. He is the holder of 11 patents and 2 pending patents. He was the Session Chair of many international conferences such as the 8th World Congress on Intelligent Control and Automation (WCICA2008), the IEEE international conferences on Information and Automation (ICIA2011) and so on.


Prof. Xu is the director of theory and education professional committee of China Medical Informatics Associationa. He is senior member of IEEE and Chinese Society of Biomedical Engineering. He is the member of the editor board for many international journals such as Physiological Measurement, Biomedical Engineering Online, Computers in Biology and Medicine and so on.

Current Research Projects

Selected Ongoing Projects:

        National Natural Science Foundation of China, Study on the key technologies of noninvasive detection of pulmonary arterial hypertension based on multi-modal data and multi-coupling model;

 

        National Natural Science Foundation of China, Online reconstruction of central aortic pulse wave based on nonlinear pulsatile tube model and multiple-channel blind identification;

        Liaoning Province Natural Science Foundation, The evaluation and optimization of the biomedical wireless sensor network based on the radiation;

        Specialized Research Fund for the Doctoral Program of Higher Education, Online optimization of noninvasive monitoring of aortic pulse wave during daily activities;

        Fundamental Research Funds for the Central Universities, Key Technologies on Noninvasive Detection of Pulmonary Hypertension Based on Multimode Data and Computational Modeling;

 

        Fundamental Research Funds for the Central Universities, Identification of the variability mechanism of cardiovascular system based on noninvasive monitoring of human body during daily activities ;

        Talent start-up funding plan of Northeastern University, design and research of intelligent monitoring and tracking system;

        Fundamental Research Funds for the Central Universities, Key technology research of multi-energy CT;

 

Details of some projects:

 

1.Estimation of Central Aortic Pulse Wave Based on Multi-channel Blind System Identification   


    Central Aortic Pulse wave (CAP) is very important in the prediction and treatment of Cardiovascular System (CVS) diseases because it provides tremendous physiological and pathological information of human CVS. In order to monitor CVS non-invasively and effectively, a new method based on Multi-channel Blind System Identification (MBSI) was proposed in this project to reconstruct CAP from two channel noninvasive Peripheral Aortic Pulse wave (PAP).

    A "Gray box" model of CVS was designed based on two-channel "T-tube" model, providing the theoretic foundation for MBSI algorithm. Effectiveness of the MBSI algorithm can be verified by the data from the “T-tube?model. In this project, the equivalence of the IIR and high order FIR function has been proved. Based on this approximation, this project successfully converts the IIR model into a FIR model, which greatly simplifies the MBSI algorithm. Verification results show that MBSI algorithm can estimate CAP stably and accurately. The overall error rate, error of systolic pressures and error of diastolic pressures produce by the MBSI algorithm are less than 7.2%, 4.6 mmHg, 4.2 mmHg respectively.



    2.Cardiovascular Primary Parameters Analysis Based on Radial Pulse Wave


    A large number of clinical results have confirmed that pulse wave contains rich information on physiology and pathology. However, noises will be introduced during the acquisition of pulse wave signal, which can influence the accuracy of the estimation of cardiovascular parameters. In this project, two parts are studied, including the processing of pulse wave and the calculation of cardiovascular parameters.

    Firstly, we proposed an adaptive denoising method based on Empirical Mode Decomposition (EMD), combining wavelet threshold method and the characteristics of noise distribution in pulse signal. In the same way, baseline drift in pulse wave was removed effectively. Then several characteristics points used to calculate cardiovascular parameters were extracted based on the threshold method. Finally, the influence factors of pulse wave such as contact pressure, tilting degrees and time duration were analyzed.

    Secondly, cardiovascular parameters (cardiac output, peripheral resistance etc.) based on K value method were calculated and the performances of the estimation were evaluated. They are almost the same under the normal pulse pressure, but they have a big difference under the larger pulse pressure. An improved formula of Cardiac Output (CO) through multiple linear regression analysis was proposed. In order to test the validity of this method, we compared the revised CO with the CO measured by the Fick Thermal-dilution method. The relative error was within 5%.


    3.Detection of R-wave in Dynamic ECG Based on Quality Analysis

 

    Nowadays, the understanding and analysis of long-term monitored electrocardiogram (ECG) in daily life still has much obstacle ahead. Electromyographic (EMG) interference is the most typical noise in dynamic ECG, and it has great influence on the detection of R-wave. We find that there are generally two types of EMG in the dynamic ECG signals: one is electricity produced by muscular relaxation or contraction, and it has rapid amplitude changes and distributes mostly at low frequency; the other is produced by holding objects and keeping still, which has a huge distraction on R-wave and has more components at higher frequency than the first type.  

    In our work, power ratio in frequency domain is used to classify EMG in different types with a long window size; the threshold-cross rate is used to classify the static ECG and dynamic ECG in a short window; the short time energy is used to classify the state of holding objects and swing arms. Combined with the results of frequency domain and time domain, the classification is reliable in short time. Dmey wavelet transform is used for dynamic ECG of holding objects in multi-scale and multi-resolution. The tendency of ECG signals could be obtained by the EMD method which could decompose signals into a limited number of Intrinsic Mode Functions (IMF). The multi-scale analysis of IMFs is used to analyze the ECG of swing arms.

    The proposed adaptive R-wave detection method has been validated using the data collected in our laboratory. Experimental results demonstrate that the proposed method is significantly applicable in dynamic ECG.

    

    4.Comprehensive Analysis of Non-invasive Cardiovascular Videos, Images and Signals   


    Early diagnosis of cardiovascular disease and prediction of cardiovascular risk based on the fusion of non-invasive cardiovascular images and non-invasive ambulatory physiological signals was proposed. Magnetic resonance imaging (MRI) has been the preferred modality for evaluation of left ventricular function and structure, whereas computed tomography (CT) has been used extensively for coronary artery calcification analysis. The analysis of volume and pressure pulse waves of peripheral arteries can be used to differentiate the functions and properties of peripheral arteries. However, in clinical practice, the analysis of these images and pulse wave signals is performed alone. These information needs to be fused in order to disclose the mechanism of the occurrence and development of cardiovascular diseases.

    

    5.Optimization on RF Radiation Effect and Signal Efficiency of Wireless Medical Devices


    Recent advances in medical, computing and information technologies have amplified the desire and possibility to develop and apply advanced wireless medical devices to improve medical and healthcare service quality, possibility and accessibility. Examples include wireless capsule endoscopes for painless examination of gastrointestinal tract and body area network (BAN) of wireless bio-sensors for patient monitoring in hospital clinic or home environments. Current efforts on wireless medical devices are concentrated on the studies of the device design, reliable communications and innovative applications. During our research on wireless medical devices and our literature search, we found that little work has been reported on systematic studies of RF radiation effect and RF signal efficiency of wireless medical devices in interaction with human body, which is a fundamentally important issue for wireless medical devices, especially for wearable and in-vivo wireless medical devices. As a result, we propose that in this research we will forge the complementary expertise of biomedical engineering, RF communications and clinical medicine to systematically study the RF radiation effect and RF signal efficiency of wearable wireless medical devices such as BAN of bio-sensors on human body and in-vivo wireless medical devices such as the wireless capsule endoscopes from inside the human body. Our overall objective is to carry out a systematic study on this topic and establish a set of design reference metrics on RF radiation effect and RF signal efficiency of wireless medical devices in interaction with human body through thorough theoretical investigations and extensive experimental studies.


Contact Info

Prof.Lisheng Xu

 

Sino-Dutch Biomedical and Information Engineering School Northeastern University.

 

E-mail: xuls@bmie.neu.edu.cn

 

Phone:

 

 

招聘：欢迎有志于生物医学电子与信号处理方面研究与教学的年轻学者申请本学院教师岗位（副教授2名、讲师2名）。

 

招生：欢迎电子信息类、数学、物理方向考生报考硕士、博士、博士后，以及年轻教师来实验室进修。要求：勤奋、踏实、有上进心。

 Selected publications

Journal papers:

        Yang Luo, Benqing Yang, Lisheng Xu, Liling Hao, Jun Liu, Yang Yao, F.N Van Vosse, “Segmentation of the left ventricle in cardiac MRI using a hierarchical extreme learning machine model,” International Journal of Machine Learning and Cybernetics, 2017, DOI:10.1007/s130412-017-0678-4.
        
        Yang Yao, Liling Hao, Lisheng Xu, Yahui Zhang, Lin Qi, Yingxian Sun, Benqiang Yang, Frans N. van de Vosse, Yudong Yao, “Diastolic augmentation index improves radial augmentation index in assessing arterial stiffness,” Scientific Reports, 2017, DOI:10.1038/s41598-017-06094-2.

 

        Dianning He, Lu Wang, Xiaobing Fan, Yang Yao, Ning Geng, Yingxian Sun, Lisheng Xu, Wei Qian, “A new mathematical model of wrist pulse waveforms characterized patients with cardiovascular disease- A pilot study,” Medical Engineering and Physics, 2017.
        
        Lu Wang, Lisheng Xu, Shuran Zhou, Hao Wang, Yang Yao, Liling Hao, Bing Nan Li, Lin Qi, “Design and implementation of a pulse wave generator based on Windkessel model using field programmable gate array technology,” Biomedical Signal Processing and Control, 36 (2017) 93-101.
        
        Zhang Y, L.S. Xu, Zhang X, Yao Y, Sun Y, Qi L. “Effects of different durations of aerobic exercise intervention on the cardiovascular health in untrained women: a meta-analysis and meta-regression,” J Sports Med Phys Fitness, 2017 May 30, PMID: 28558443, doi: 10.23736/S0022-4707.17.07029-3.
        
        Junxin Chen, Yu Zhang, Lin Qi, Lisheng Xu, “Exploiting chaos-based compressed sensing and cryptographic algorithm for image encryption and compression,” Sep 2017, Optics & Laser Technology.
        
        Xiaoqing Yi, Liling Hao, Fangfang Jiang, Lisheng Xu, Shaoxiu Song, Xian Liu, Ling Lin, “Synchronous acquisition of multi-channel signals by single-channel ADC based on square wave modulation,” Aug 2017, Review of Scientific Instruments.
        
        Dianning He, Wei Qian, Lisheng Xu, Xiaobing Fan, “Using numerical simulations and experiments to compare different pure mathematical models for analyzing dynamic contrast enhanced MRI data,” Mar 2017, Current Medical Imaging Reviews, DOI: 10.2174/1573405613666170322162243
        
        Yang Yao, Lisheng Xu, Yingxian Sun, Qiang Fu, Shuran Zhou, Dianning He, Yahui Zhang, Liang Guo, and Dingchang Zheng, “Validation of an adaptive transfer function method to estimate the aortic pressure waveform,” IEEE Journal of Biomedical and Health Informatics, 2016, DOI: 10.1109/JBHI.2016.2636223.

 

        Yueyang Teng, Shouliang Qi, Dayu Xiao, Lisheng Xu, Jianhua Li, Yan Kang, “A general solution to least squares problems with box constraints and its applications,” Mathematical Problems in Engineering, 2016(2): 1-11.
        
        Dongqi Wang, Dongming Chen, Ben Ma, Lisheng Xu, Jiliang Zhang, “A high capacity spatial domain data hiding scheme for medical images,” J Sign Process Syst, (2016). doi:10.1007/s11265-016-1169-7
        
        Hongrui Bo, Lisheng Xu, Liling Hao, Yuanzhu Dou, Lei Zhao, and Wenhua Yu, “A single-channel non-orthogonal I/Q RF sensor for non-contact monitoring of vital signs,” Applied Computational Electromagnetics Society Journal, 2016, 31(6):603-611.
        
        L Hao, L Xu, B Yang, G Li, “Image reconstruction based on the anatomical information for magnetic resonance electrical impedance tomography,” Applied Computational Electromagnetics Society Journal, 2016, 31(6):700-705.
        
        L Hao, L Xu, “Joint L-1 and total variation regularization for magnetic detection electrical impedance tomography,” Applied Computational Electromagnetics Society Journal, 2016, 31(6):677-683.
        
        Y Zhang, L Xu, Y Yao, X Guo, Y Sun, et.al. “Effect of short-term exercise intervention on cardiovascular functions and quality of life of chronic heart failure patients: a meta-analysis”, Journal of Exercise Science & Fitness, 2016, 14 (2):67-75.
        
        Y Teng, S Qi, Y Dai, L Xu, W Qian, K Yan, “Semi-supervised Nonnegative Matrix Factorization with Commonness Extraction” Neural Processing Letters, 2016, 45(3):1-14.
        
        Lu Wang, Lisheng Xu, Dazhe Zhao, Yang Yao, Dan Song, “FPGA-based design and implementation of arterial pulse wave generator using piecewise Gaussian–cosine fitting,” Computers in Biology and Medicine, 59(2015): 142-151.
        
        Lisheng Xu, Yahui Zhang, Yang Yao, Ruifeng Zhang, Liping Chou, “Study on the effect of endurance training on HRV in athletes,” Heart Rate Variability (HRV) Prognostic Significance Risk Factors and Clinical Applications, Nova Science Publishers, New York, 2015.(Book chapter)
        
        Lili Niu, Long Meng, Lisheng Xu, et al.,“Stress phase angle depicts differences in arterial stiffness: phantom and in vivo study,” Physics in Medicine & Biology, 60(2015), 4281-4294.
        
        Lu Wang, Nelson Yung, Lisheng Xu, "Multiple Human Tracking by Iterative Data Association and Detection Update”, IEEE Transactions on Intelligent Transportation Systems. 2014, 15(5): 1886-1899.
        
        Lisheng Xu, Yang Yao, Hao Wang, Dianning He and Lu Wang, “Morphology variability of radial pulse wave during exercise,” Biomedical Materials and Engineering, 24(2014) 3605-3611.
        
        Liling Hao, Gang Li, and Lisheng Xu, “Magnetic detection electrical impedance tomography with total variation regularization,” Biomedical Materials and Engineering, 24(2014) 2857-2864.
        
        Lu Wang, Lisheng Xu, Shuting Feng, Max Q.-H. Meng, Kuanquan Wang, “Multi-Gaussian fitting for pulse waveform using Weighted Least Squares and multi-criteria decision making method,” Computers in Biology and Medicine, Vol. 43, no. 11, 2013, November, pp. 1661-1672.
        
        Lisheng Xu, Dianning He, Yue Zhao and Sainan Yin, "Recent advance in noninvasive continuous blood pressure measurement system," Recent patents on Biomedical Engineering, 2013, 6, 170-178.
        
        L.S. Xu, and Max Q.-H. Meng, and C. Hu, “Effects of Dielectric Values of Human Body on Specific Absorption Rate (SAR) Following 430, 800 and 1200 MHz Radio Frequency Exposure to Ingestible Wireless Device,” IEEE Transactions on Information Technology in Biomedicine, January 2010, vol. 14, pp. 52-59.
        
        L.S. Xu, Max Q.-H. Meng, X.H. Qi, K.Q. Wang, “Morphology Variability Analysis of Wrist Pulse Waveform for Assessment of Arteriosclerosis Status,” Journal of Medical Systems, 2010, 34: 331-339.
        
        L.S. Xu, Max Q.-H. Meng and K.Q. Wang, “Pulse Image Recognition Using Fuzzy Neural Network,” Expert Systems with Applications, 2009, 36: 3805-3811.
        
        L.S. Xu, Max Q.-H. Meng, and Y.W. Chan, “Effects of Dielectric Parameters of Human Body on Radiation Characteristics of Ingestible Wireless Device at Operating Frequency of 430 MHz,” IEEE Transactions on Biomedical Engineering, 56(8):2083-94.
        
        L.S. Xu, Max Q.-H. Meng, H.L Ren, and Y.W. Chan, “Radiation Characteristics of Ingestible Wireless Devices in Human Intestine Following Radio Frequency Exposure at 430, 800, 1200 and 2400 MHz,” IEEE Transactions on Antennas and Propagation, Aug. 2009, 57(8): 2418-2428.
        
        L.S. Xu, D. Zhang, K.Q. Wang, N.M. Li and X.Y. Wang, “Baseline Wander Correction in Pulse Waveforms Using Wavelet-Based Cascaded Adaptive Filter,” Computers in Biology and Medicine, Vol 37, No 5, May 2007, pp. 716-731.
        
        L.S. Xu, D. Zhang, and K.Q. Wang, and L. Wang, “Arrhythmic Pulses Detection Using Lempel-Ziv Complexity Analysis,” EURASIP Journal on Applied Signal Processing 2006 (2006), Article ID 18268, 12 pages.
        
        L.S. Xu, D. Zhang, and K.Q. Wang, “Wavelet-based Cascaded Adaptive Filter for Removing Baseline Drift in Pulse Waveforms,” IEEE Transactions on Biomedical Engineering, vol.52, no.11, Nov. 2005, pp. 1973-1975.



 

Conference papers:

 

        W Qian, L Qi, L Xu, Y He, F Zhao, et al., Finite element analysis of a new type of post dilatation balloon catheter in PCI, The 5th International Conference on Computational and Mathematical Biomedical Engineering (CMBE2017), 10-12 April 2017, USA, pp. 876-879.
        
        Yahui Zhang, Lin Qi, Lisheng Xu, Chenglin Du, "Acute effects of incremental exercise on central hemodynamics in young basketball athletes," The 39th Annual International Conference of the IEEE Engineering in Medicine and Biology Society (EMBC), July 2017, Korea, DOI: 10.1109/EMBC.2017.8037084
        
        Cheng Shi, Yu Zhang, Qingyue Gong, Jinhai Zhou, Lisheng Xu, “The study of pulse image of traditional Chinese medicine in information age,” Medinfo2017, 21-25 August 2017, Hangzhou, China. Pages 586-588, DOI 10.3233/978-1-61499-830-3-586
        
        Rui Chai, Li-sheng Xu, Yang Yao, Li-ling Hao, Lin Qi, Comparison of Regression Analysis and Transfer Function in Estimating the Parameters of Central Pulse Waves from Brachial Pulse Wave, Medinfo2017, 21-25 August 2017, Hangzhou, China. Pages.573-577, DOI-10.3233/978-1-61499-830-3-573
        
        Zengzhi GUO, Wenjun TAN, Lisheng XU, Lu WANG, et al., “A level set segmentation method of the right ventricle in cardiac MRI images based on motion intensity,” Proceedings of the 17th China-Japan-Korea Joint Symposium on Medical Informatics, 22nd November, 2016, Pacifico Yokohama, Japan, 62-65.
        
        Hongrui BO, Qiang Fu, Lisheng XU, et al., “Design and Implementation of a 2.45 GHz RF Sensor for Non-contacting Monitoring Vital Signs,” Computing in Cardiology, 43: 1113-1116, 2016.09.11-14, Vancouver, BC, Canada.
        
        Yang YAO, Qiang Fu, Lisheng Xu, Yu Wang, Yahui Zhang, Yingxian Sun, Liang Guo, “Diastolic Augmentation Index Improves Augmentation Index in Assessing Arterial Stiffness,” Computing in Cardiology, 43:189-192, 2016.09.11-14, Vancouver, BC, Canada.
        
        Hongyu Kang, Lisheng Xu, Wenlong Lv and Wei Qian, Jun Liu, Benqiang Yang and Mingyu Zou, “Noninvasive estimation of pressure difference of left and right ventricle based on Young - Laplace model,” Proceedings of the IEEE International Conference on Information and Automation Ningbo, China, August 2016, pp.702-76.
        
        Yang Luo, Benqiang yang, Lisheng Xu, et al., “Segmentation of the left ventricle in cardiac MRI using an ELM model,” Proceedings of The International Conference on Extreme Learning Machine (ELM2015), Hangzhou, China, December 15-17, 2015.
        
        Yang Yao, Lisheng Xu, et al, “Validation of a transfer function method to estimate the aortic pressure waveform,” Proceedings of The 16th China–Japan–Korea Joint Symposium on Medical Informatics (CJKMI 2015)
        
        Dianning He, Li Zheng, Jia Liu, Ning Geng, Lisheng Xu, Dejun Guan, "Variation of Radial Pulse Wave Contour Influenced by Contact Pressure," Proceedings of 36th Annual International Conference of the IEEE Engineering in Medicine and Biology Society, Scheduled for presentation on Friday August 29, 2014, 15:30-17:00 hrs.
        
        Li Zheng, Lu Wang, Dianning He, Ning Geng, Lisheng Xu, Dejun Guan, Ping Geng, "Voltage compensation based calibration measurement of 3D-acceleration transducer in fall detection system for the elderly," Proceedings of 36th Annual International Conference of the IEEE Engineering in Medicine and Biology Society, Scheduled for presentation on Thursday August 28, 2014, 09:30-11:00 hrs.
        
        Jinye Zhao, Li Zheng, Lu Zhao, Yingwei Fan, Yuanzhu Dou, Lisheng Xu, “Design and implementation of a printed Yagi antenna working at the frequency of 2.4GHz for monitoring physiological parameters,” Proceeding of the 11th World Congress on Intelligent Control and Automation (WCICA2014), Shenyang, China, June 29 - July 4 2014, pp.543-548.
        
        Yang Yao, Liling Hao, Ning Geng, Yueming Jin, Shangjie Du, Lisheng Xu, “Estimation of carotid artery pressure waveform by transfer function and radial pressure waveform,” Proceeding of the 11th World Congress on Intelligent Control and Automation (WCICA2014), Shenyang, China, June 29 - July 4 2014, pp.6081-6084.
        
        Yingfei Su, Yahui Zhang, Yueming Jin, Yang Yao, Ruifeng Zhang, Yongsheng Jiang, Lisheng Xu, “The feasibility for dicrotic augmentation index to replace tidal augmentation index,” Proceeding of the IEEE International Conference on Information and Automation (IEEE ICIA2014), Hailar, China, July 2014, pp.943-948.
        
        L.S. Xu, Guo Xu, Yang Feifei, Yin Sainan, Zhang Xibin, Meng Max Q.-H., “Implementation of Cuff-less Continuous Blood Pressure Measurement System Based on Android,” Proceedings of 2012 IEEE International Conference on Information and Automation (ICIA2012), p 552-556, 2012.
        
        L.S. Xu, S.T. Feng, Y. Zhong, C. Feng, Max Q.-H. Meng, et al., “Multi-Gaussian Fitting for Digital Volume Pulse Using Weighted Least Squares Method,” Proceedings of the IEEE International Conference on Information Automation (ICIA2011), June 6-8, 2011, pp. 52-57.
        
        L.S. Xu, Cong Feng, Ying Wang,Yupeng Yao, Max Q-H. Meng, “A method for recognizing noises in pulse waves,” Proceedings of the 8th World Congress on Intelligent Control and Automation (WCICA2010), July 6-9, 2010, Jinan, China, pp. 2264-2268.
        
        L.S. Xu, Max Q.-H. Meng, and B.P. Li, “Effects of Dielectric Values of Human Body on Specific Absorption Rate (SAR) Following 800 MHz Radio Frequency Exposure to Ingestible Wireless Device,” Proceedings of 31st Annual International Conference of the IEEE Engineering in Medicine and Biology Society (EMBC2009), 2009.
        
        L.S Xu, Max Q.-H. Meng, R. Liu, K.Q. Wang, “Robust Peak Detection of Pulse Waveform Using Height Ratio,” Proceedings of the 30th Annual International Conference of the IEEE Engineering in Medicine and Biology Society (EMBC2008), 2008, pp. 3856-3859.
        
        L.S. Xu, Max Q.-H. Meng and K.Q. Wang, “Pulse Image Recognition Using Fuzzy Neural Network,” Proceedings of the 29th International Conference of the IEEE Engineering in Medicine and Biology Society (EMBC2007), 22-26 Aug. 2007 pp. 3148-3151.
        
        L.S. Xu, K.Q. Wang, L Wang, N.M. Li, “Pulse Contour Variability before and after Exercise,” 19th IEEE International Symposium on Computer-Based Medical Systems (CBMS 2006), 22-23 June 2006 in Salt Lake City, Utah USA, pp. 237-240.
        
        L.S. Xu, K.Q. Wang and L. Wang, “Pulse Waveforms Classification Based on Wavelet Network,” 27th International Conference of the IEEE Engineering in Medicine and Biology Society (EMBC2005), Shanghai, China, 01-04 Sept. 2005, pp.4596 - 4599.