Bioelectric Signal Processing

Richard G. Shiavi, Ph.D.

Description of Research Program

Current Projects

Recent Publications

Textbook

Biographical Summary

Description of Research Program:

There are several ongoing projects which involve collaboration between the Departments of Biomedical Engineering and Electrical Engineering and Departments within Vanderbilt University Medical Center.  These projects are briefly described below.

Current Projects Include:

1.     Clinical Research Center - Dysfunction of the autonomous nervous system (ANS) results in various disorders of the cardiovascular system (CVS), for instance, in the control of blood pressure.  The performance of the CVS in response to various therapeutic interventions is being studied through the measurement of blood pressure, cardiac activity, etc.  In addition, the microneurogram is recorded in order to study the nervous control of the ANS. Analytic techniques are being developed for the purpose of relating ANS activity and CVS performance.

2.                Departments of Biomedical Engineering, Electrical Engineering, and Psychiatry  – Acoustic properties of speech have been identified as possible cues to depression and there is evidence that certain vocal parameters may be used further to objectively differentiate depressed individuals from individuals at high risk for suicide. Studies are being performed to analyze the acoustics of speech within normal, depressed and suicidal populations. Multivariate statistical analyses reveal that there is potential in using formants and power spectra to provide an accurate prediction of mental state..

Recent Publications:

Shiavi, R., Frigo, C., and Pedotti, A.; EMG Signals during Gait: Criteria for Envelope Filtering and Number of Strides. Medical & Biological Engineering & Computing; 36:171-178, 1998.

Baker, L. and Shiavi, R.; Detection of Microneurographic Activity and Estimation of Burst Parameters. Computers in Biology and Medicine; 29:175-189, 1999.

Shiavi, R., Learning Signal Processing Using Interactive Notebooks. IEEE Transactions on Education; 42:355-CD, 1999.

Shiavi, R., Bourne, J., Brodersen, A., and White, E., Introduction to Computing in Engineering. In Interactive Learning: Vignettes from America's Most Wired Campuses, David Brown, ed.; Anker Publishing Co., Bolton MA, 2000.

Shiavi, R., Teaching Signal Processing Using Notebooks. In Interactive Learning: Vignettes from America's Most Wired Campuses, David Brown, ed.; Anker Publishing Co., Bolton MA, 2000.

France, D., Shiavi, R., Silverman, S., Silverman, M., and Wilkes, M.; Acoustical Properties of Speech as Indicators of Depression and Suicidal Risk. IEEE Transactions on Biomedical Engineering; 47:829-837, 2000.

Furlan, R., Porta, A., Costa, F., Tank, J., Baker, L., Schiavi, R., Robertson, D., Malliani, A., and Mosqueda-Garcia, R.; Oscillatory Patterns in Sympathetic Neural Discharge and Cardiovascular Variables During Orthostatic Stimulus. Circulation; 1010:886-892, 2000.

Ertl, A., Diedrich, A., et al. including Shiavi, R.; Human Muscle Sympathetic Nerve Activity and Plasma Noradrealine Kinetics in Space. Journal of Physiology; 538.1:321-329, 2002.

Kennedy, J., Gwertsman, H., Schmidt, D., Shiavi, R. et al.; Serial Cerebral Spinal Fluid Tryptophan and 5-hydroxyindoleacitic Acid Concentrations in Healthy Human subjects. Life Sciences Journal; 71:1703-1715, 2002.

André Diedrich, Warakorn Charoensuk, Robert J Brychta, Andrew C. Ertl, Richard Shiavi^, "Analysis of Raw Microneurographic Recordings based on Wavelet De-noising Technique and Classification Algorithm". IEEE Transactions on Biomedical Engineering; 50:41-50, 2003.

Li-Qun Zhang , R. G. Shiavi, T.J. Limbird, Jay M. Minorik, "Six Degrees-of-Freedom Kinematics of ACL Deficient Knees during Locomotion-Compensatory Mechanism". Gait and Posture, 17:34-42, 2003.

Ertl AC, Diedrich A, Paranjape S, Biaggioni I, Robertson RM, Lane LD, Shiavi R, Robertson D. The human sympathetic nervous system response to spaceflight.  In: The Neurolab Spacelab Mission: Neuroscience Research in Space. Buckey, J.C. and Homick J.L. Eds. NASA SP-2003-535, NASA-Johnson Space Center, Houston, Texas, 2003.

Ozdas, A., R.G. Shiavi, D.M. Wilkes,  M.K. Silverman, and S.E. Silverman, "Analysis of Vocal Tract Characteristics for Near-term Suicidal Risk Assessment". Methods of Information in Medicine, 43:36-38, 2004.

Ozdas, A., R.G. Shiavi, D.M. Wilkes,  M.K. Silverman, and S.E. Silverman, "Investigation of Vocal Jitter and Glottal Flow Spectrum as Possible Cues for Depression and Near-Term Suicidal Risk". IEEE Transactions on Biomedical Engineering: 51:1530-1540, 2004.

Shiavi, R. and Frigo, C., "Applications in Movement and Gait Analysis". In Electromyography: Physiology, Engineering, and Non-Invasive Applications by Merletti and Parker, P. John Wiley & Sons, Inc., 2004.

Salomon RM, Kennedy JS, Johnson BW, Urbano Blackford J, Schmidt DE, Kwentus J, Gwirtsman HE, Gouda JF, Shiavi RG. "Treatment Enhances Ultradian Rhythms of CSF Monoamine Metabolites in Patients with Major Depressive Episodes". Neuropsychopharmacology; 30(11):2082-91, 2005.

Shiavi, R., A. Brodersen, "Study of Instructional Modes for Introductory Computing". Journal of Engineering Education; 94(4):355-362, 2005.

Brychta, R. J., S. Tuntrakool, et al. (2006). "Wavelet Methods for Spike Detection in Mouse Renal Sympathetic Nerve Activity using the Stationary Wavelet Transform with Automated Noise Level Estimation." IEEE Transaction on Biomedical Engineering In Press.

Textbook:

Shiavi, R.  Introduction to Applied Statistical Signal Analysis, Second Edition. Academic Press, San Diego, 1999.

The textbook is accompanied by a CD which contains digitized measured signals from a variety of sources and a set of MATLAB notebooks which provide interactive exercises for students. These notebooks were developed with the MATLAB Notebook Toolbox. This toolbox enables the integration of Microsoft (MS) Word and MATLAB computing environment. Each notebook is an MS Word file which contains both text and MATLAB script. The text presents a signal processing principle and the script demonstrates its implementation. The output is returned within the MS Word document. The student is then asked to exercise other aspects of the principle interactively by making simple changes in the MATLAB script. The student then receives immediate feedback concerning what is happening and can relate theoretical concepts to real effects upon a signal.¹ 

The notebooks were developed under MATLAB version 5.3. Some time ago version 6 was released. Several functions implementing autoregressive modeling had their structure changed such that script written for version 5.3 is not forward compatible. This effected two notebooks. The upgraded versions, armod_v6.doc and psdest_v6.doc are downloadable from the links shown. Also an additional notebook regarding stationarity, stationarity.doc, is available.

¹Shiavi, R., Learning Signal Processing Using Interactive Notebooks. IEEE Transactions on Education; 42:355-CD, 1999.    

Biographical Summary:

Richard Shiavi received his BE degree in Electrical Engineering from Villanova University in 1965 and MS and Ph.D. degrees in Biomedical Engineering from Drexel University in 1969 and 1972 respectively. From 1965 through 1967 he served as a line officer in the US Navy.

         Since 1972, Dr. Shiavi has been actively engaged in teaching and research at Vanderbilt University and the Veterans Administration Medical Center and is currently Professor of Biomedical Engineering and Professor of Electrical Engineering. For 20 years he was involved in the study of electromyographic synergy patterns and knee kinematics during normal and pathologic human locomotion. He has been a collaborator with the Centro di Bioingegneria of the Politecnico di Milano. More recently he has been actively engaged in two other areas of research. One concerns quantifying the functionality of the autonomic nervous system and is done as a collaborator in the Clinical Research Center at Vanderbilt University Medical Center. He was fortunate to be a member of the Neurolab Spacelab Mission Science Team which investigated the effect of microgravity on control of the autonomic nervous system. The other project concerns speech correlates of suicidality. His main professional interests are in applications of signal processing techniques and signal measurement. Research publications appear in the literature and congress proceedings of biomedical engineering and biomechanics and he has written book chapters for the "Handbook of Pattern Recognition and Image Processing" and "Gait and Rehabilitation".

         More recently he has been involved with innovations in engineering education.  He has written a textbook entitled “Introduction to Applied Statistical Signal Analysis” which includes a series of interactive notebooks in MATLAB for teaching signal processing. An article about these notebooks appeared in the IEEE Transactions on Education.

        Dr. Shiavi has been an active member of Institute of Electrical and Electronic Engineers (IEEE), has served in the Engineering in Medicine and Biology Society (EMBS) in various capacities. He has served as the Region 3 representative to the Administrative Committee for the 1986‑1987 term, has held offices of the Nashville EMBS Section and served several times as an Associate Editor for the IEEE Transactions on Biomedical Engineering. During February of 1996 Dr. Shiavi was appointed as a Fellow in the American Institute for Medical and Biological Engineering. In 1998 he was recognized as one of Distinguished Alumni of the School of Biomedical Engineering, Science, and Health Systems of Drexel University.