Distinguished McKnight University Professor of Biomedical Engineering
Medtronic-Bakken Chair for Engineering in Medicine
Director, Institute for Engineering in Medicine
Director, Center for Neuroengineering
Website: Biomedical Functional Imaging and Neuroengineering Laboratory
Dr. Bin He's major research interests are in the field of neuroengineering and biomedical imaging. Together with his co-workers, he has made significant contributions to the development of electrophysiological functional imaging, multimodal imaging, cardiac electric imaging, and neuroengineering. Dr. He's research programs are funded by NIH (NIBIB, NHLBI, NEI), NSF, and ONR among other sponsors. The active research programs in Dr. He's lab are as follows.
Multimodal Functional Neuroimaging: Dr. He and his students have developed a unified theory for multimodal neuroimaging integrating the BOLD functional MRI and electrophysiological imaging. Hemodynamic neuroimaging, such as BOLD functional MRI, has high spatial resolution at mm scale but very slow in time. Electrophysiological neuroimaging has high temporal resolution at ms scale but limited spatial resolution. It has been a major frontier in the functional neuroimaging research to attempt to greatly enhance spatio-temporal resolution by integrating functional MRI with electrophysiological imaging. Dr. He and colleagues have developed a rigorous theory on neurovascular coupling, which provides a principled way of integrating BOLD functional MRI signals with electrophysiological signals for event-related paradigms. The theory has been tested in human visual system and revealed a dramatic improvement in performance in imaging human visual information pathways. Dr. He and his students have further developed new algorithms to integrate fMRI and EEG/MEG signals for oscillatory brain activity. Currently both theoretical and experimental studies are actively pursued in Dr. He's lab to further develop the high resolution spatio-temporal functional neuroimaging modality, and to study the sensory, motor and cognitive functions of the brain using EEG/fMRI.
Functional Neuroimaging of Epilepsy: Dr. He and colleagues have made significant contributions to high-resolution electrophysiological neuroimaging aiding neurosurgical planning in epilepsy patients. Due to the limited spatial resolution of scalp EEG, it is widely practiced in clinical settings that invasive intracranial recordings are obtained, by placing electrode sensors directly on the surface of or within the brain, to aid neurosurgical planning in patients with intractable epilepsy. Dr. He and his students have developed an innovative epilepsy source imaging methodology, in which causal interactions among sources are identified and imaged from noninvasive EEG recordings. Such imaging provides high spatial resolution in imaging distributed brain sources within the 3-dimensional brain volume and reveals neural interactions and connectivity embedded in the brain networks. Dr. He and colleagues have further developed an ICA based seizure imaging methodology and conducted a rigorous validation study in a group of epilepsy patients to image epileptogenic brain, and demonstrated high consistence between the imaged seizure sources and the epileptogenic zones determined by well established clinical procedures in the same patients. Active research is currently being pursued to further establish electrophysiological neuroimaging as a noninvasive tool aiding surgical planning in epilepsy patients. Other than EEG/MEG neuroimaging, Dr. He and his colleagues are also pursuing functional MRI mapping of epileptogenic zone from fMRI. This line of work is carried in collaboration with Mayo Clinic and University of Minnesota Medical Center.
Electrical Properties Imaging: An important research program in Dr. He’s lab is the development and investigation of novel approaches for noninvasive imaging of electrical properties of biological tissues, including bioimpedance imaging. Dr. He and colleagues have proposed and developed a new approach called magnetoacoustic tomography with magnetic induction (MAT-MI) by integrating ultrasound and biomagnetism, in order to obtain high resolution image of electrical impedance of biological tissue. In the MAT-MI approach, the object is placed in a static magnetic field and a pulsed magnetic field. The pulsed magnetic field induces eddy current in the object. Consequently, the object emits ultrasonic waves through the Lorentz force produced by the combination of the eddy current and the static magnetic field. The acoustic waves are then collected by the detectors located around the object for image reconstruction. MAT-MI takes the advantage of excellent contrast of electrical impedance and the high spatial resolution of ultrasound. The recent work demonstrates that the MAT-MI approach can achieve mm spatial resolution in imaging electrical impedance, which represents a significant advancement in comparison with the spatial resolution of conventional electrical impedance imaging approach, and may play a critically important role in early detection of breast cancer. Along the similar line, Dr. He and his colleagues have been developing a MR based electrical properties tomography (EPT) approach using B1 mapping of MR technology to reconstruct subject specific electrical properties distributions. EPT not only has great potential for clinical applications in cancer detection and diagnosis but also promises to provide subject specific SAR mapping, helping managing safety concerns in high or ultrahigh field MRI systems.
Cardiac Electrical Tomography: Dr. He and colleagues have pioneered the development of electrophysiological cardiac tomography in assessing dynamic cardiac functions. The electrocardiographic inverse imaging problem has historically been solved using point dipole sources, epicardial potentials, or heart surface activation patterns. Dr. He and colleagues have developed cardiac electrical tomography techniques in his lab to image electrical functional information throughout the 3-dimensional volume of the heart from noninvasive electrocardiographic measurements. In collaboration with collaborators at the University of Alabama at Birmingham and the University of Minnesota Medical School, Dr. He and colleagues have validated this cardiac electrical tomography technology in animal models including rabbits, dogs, and swines where simultaneous intracardiac or intracavity potentials are measured together with body surface potential mapping. Dr. He has recently further proposed a catheter-based cardiac electrical tomography approach to use the minimally invasive catheter recordings, which is routinely used in numerous hospitals in the world. Currently pilot clinical studies are being carried out to test the efficacy and clinical applications of the cardiac electrical tomography techniques developed in Dr. He’s lab. The establishment of such imaging techniques promises to greatly impact the management of cardiac arrhythmia, a leading cause of public health problem in US and developed countries.
Brain-Computer Interface: Dr. He and his students have made significant contributions to brain-computer interface (BCI) research. This work is aimed at developing novel techniques for effectively decoding the intention of human subjects and controlling external device which may ultimately benefit patients suffering from neurological disorders. Dr. He and his students have developed a time-frequency-spatial approach to extract the extremely weak signals accompanying the “thought” of a human subject using an array of electrode sensors placed over the scalp. This method takes the “signatures” of each individual subject and uses them for optimal decoding of the intention of the human subject. Dr. He has proposed the concept of electrophysiological neuroimaging based BCI – an idea to estimate “virtual” intracranial signals from the noninvasive EEG recordings for substantially improving the performance of noninvasive EEG based BCI. Dr. He and his colleagues have been aggressively investigating the mechanisms associated with motor imagery based BCI by using advanced neuroimaging techniques to delineate the brain sources accompanying motor imagery. Recently, Dr. He and his students have developed a 3-dimensional continuous brain-computer interface system to allow human subjects to control the flight of a flying robot from noninvasive brain waves. Click the video to see the mind controlled flying robot.
Neuromodulation: Dr. He and his colleagues are actively pursuing noninvasive neuromodulation modalities including transcranial magnetic stimulation (TMS) and transcranial direct current stimulation (tDCS). Current interest ranges from basic studies of mechanisms of TMS and tDCS by means of dynamic brain mapping, to clinical investigations in patients with stroke and schizophrenia. Other than treatment purposes, Dr. He and his colleagues are pursuing perturbation based imaging in which neuromodulation is used to perturb the central nervous systems and responses measured using various neuroimaging methods for better understanding of brain circuits, networks and functions.