I received my PhD from MIT in 1959 in physics, writing a dissertation on electron paramagnetic resonance (EPR), spent 16 years at Varian Associates heading their EPR research and development program, and came to MCW in 1975 as Professor of Biophysics to help establish the National Biomedical EPR Center, a P41 Research Resource supported by the National Center for Research Resources of NIH. The grant has recently been transferred to the National Institute of Biomedical Imaging and Bioengineering (NIBIB) and will be renewed until 2013, which will be the 36th year of funding. I continue to serve as director of the EPR Center.
My personal interest in EPR, with support from two R01 awards as well as the P41 grant, is to contribute to the development of EPR instrumentation and to extend the ways in which existing EPR instrumentation can be used for new categories of biomedical problems. Our papers on multiquantum EPR and pulse saturation recovery EPR are not only examples of interesting spin physics but also hold great promise for research using site-directed spin labeling (SDSL), such as the programs of research by my colleagues at MCW, Drs. Feix and Klug. Our papers on time-locked sub-sampling (TLSS) detection bring modern digital signal acquisition methods to EPR spectroscopy. It is believed that the techniques described in these papers will serve as the foundation for the next generation of EPR spectrometers. We have developed a digital detection spectrometer for use at Q-band. This instrument can be used for multiquantum EPR and ELDOR, standard EPR, and saturation recovery and pulse ELDOR EPR. We have recently extended these capabilities to W-band using frequency-translation technology.
In the last few years, we have published a series of papers on EPR sample-containing resonators using finite element modeling of electromagnetic fields. We studied the effect of an aqueous sample on field distribution, defined a new principle for design of aqueous-sample cuvettes, and invented a new class of resonators – the so-called Uniform-Field cavities. These advances would hardly have been possible without improved software and increased computing power.
In 1984, I became interested in MRI, which led to a program of research and development of surface coils and gradient coils. My students and I wrote the first paper on functional magnetic resonance imaging (fMRI) of the sensorimotor system in human brain in 1992, as well as the first paper on functional connectivity MRI, now called fcMRI, in 1995. Since the acquisition of the 9.4T small-animal scanner, my interests have increasingly shifted to fMRI and fcMRI in rat brain at high spatial resolution. I have an active collaboration with reconstructive surgeons in the Department of Plastic Surgery. Manipulation of the nerves of the rat forelimb, including use of embedded electrodes, nerve transection, and nerve transfer, is leading both to new insights in neuroscience and to new opportunities in translational research. A just-funded new project in collaboration with the Department of Radiology involves real-time analysis of fMRI and fcMRI data from patients. We propose to develop new ways to deal with the problem of motion, which can be severe in individuals who are ill or elderly.
EPR and MRI research is carried out in cooperation with staff engineers and scientists, several long-standing collaborators including W. Froncisz from the Jagiellonian University in Krakow, Poland, and pre-doctoral students as well as postdoctoral fellows.