Education

• B.S.E.E., Brigham Young University, 1962.
• M.S., Stanford University, 1963.
• Ph.D., University of Utah, 1967.
• Dissertation: "Double-Stream Instabilities in Electron Beams and Semiconductors."
• Postdoctoral (Bioengineering), University of Washington, 1972-1974.

Professional Data

• University of Utah, Electrical Engineering Department, Assistant Professor, 1971-1978;

Associate Professor, 1978-1983; Professor, 1983-present; Director of Graduate Studies, 1977-1983.

• University of Utah, Bioengineering Department; Assistant Professor, 1974-1978;

Associate Professor, 1978-1983; Professor, 1983-present; Chairman, 1985-1988.

• Cornell University, Ithaca, New York, Visiting Professor, Electrical Engineering Department

and Submicron Facility, 1984-1985.

• University of Washington, Seattle, Washington, Visiting Scholar, 1972-1974.
• University of California, Santa Barbara, California, Researcher, 1970-1971.
• General Motors Research Laboratories, Santa Barbara, California, 1966-1971.
• International Business Machines Corporation, San Jose, California, summer 1963.
• Hewlett-Packard Company, Palo Alto, California, summer 1962.
• Bell Telephone Laboratories, Inc., Murray Hill, New Jersey, summer 1961.

Teaching Activities

• Fourier Optics and Holography: ECE 6420, taught Fall 2006.
• Ultrasound: Bioen 5480/ECE 5480, taught Fall 2006.
• Senior Thesis I & II: ECE 4900 & 4910, taught Fall 2006 and Spring 2007.

Research Interests

Waves used for biological applications, including optical biosensors, ultrasonic imaging and ultrasonic energy delivery.
Current projects include:

Planar-Waveguide Fluorescence Immunosensor:

The evanescent portion of a waveguided laser beam excites fluorescence when an analyte being measured binds to antibodies immobilized on the surface of a planar waveguide. This homogeneous assay is rapid and does not require operator wash steps. Using disposable cartridges, the system is now being studied as a clinical point-of-care sensor and for biological warfare detection. The project is in collaboration with Prof. Jim Herron.

Ultrasonic Enhancement of Drug Delivery:

Ultrasound modifies the release and uptake of drug delivered to tissues.  Localizing the action of a drug to targeted tissues increases the effectiveness of the treatment while sparing untargeted tissue. These projects are being carried out in collaboration with Profs. Natalya Rapoport and William Pitt.

Modeling of Therapeutic Ultrasound:

Ultrasound can be used as an energy delivery means.  It has found use as a drug-delivery modality, in bone healing, and in tissue heating and ablation.  To model the path of the ultrasound beam in imhomogeneous tissue, we have developed a numerical technique called the fast hybrid angular spectrum method (HAS).  This project is in collaboration with Profs. Bob Roemer, Dennis Parker and Mikhail Skliar.

Books

• D. A. Christensen, Ultrasonic Bioinstrumentation John Wiley & Sons, New York, January 1988. Click here to see more

• C.H. Durney and D. A. Christensen, Basic Introduction to Bioelectromagnetics, CRC Press, Boca Raton, Florida, August 1999.  Click here to see more

Recent Publications

• D.N. Buechler, D.A. Christensen, C.H. Durney and B. Simon, “Calculation of Electric Fields Induced in the Human Knee by a Coil Applicator,” Bioelectromagnetics , vol. 22, issue 4, pp. 224-232, 2001.
• D.N. Buechler, D.A. Christensen, C.H. Durney and B.J. Simon, “Calculation of Electric Fields in the Human Knee Produced by a Knee-Thigh Electrode Pair,” Applied Computational Electromagnetics Society Journal , vol. 16, no. 2, pp.173-180, July 2001.
• G.A. Husseini, N.Y. Rapoport, D.A. Christensen, J.D. Pruitt and W.G. Pitt, “Kinetics of Ultrasonic Release of Doxorubicin from Pluronic P105 Micelles,” Colloids and Surfaces B: Biointerfaces , vol. 24, no. 3-4, pp. 253-264, 2002.
• G.A. Husseini, D.A. Christensen, N.Y. Rapoport, and W.G. Pitt, “Ultrasonic Release of Doxorubicin from Pluronic P105 Micelles Stabilized with an Interpenetrating Network of N,N-diethylacrylamide,” Journal of Controlled Release , vol. 83, pp. 303-305, 2002.
• N. Rapoport, A. Marin and D. A. Christensen, “Ultrasound-Activated Micellar Drug Delivery,” Drug Delivery Systems and Sciences , vol. 2, no. 2, pp. 37-46, June/July 2002.
• A. Marin, H. Sun, G.A. Husseini, W.G. Pitt, D.A. Christensen and N.Y. Rapoport, “Drug Delivery in Pluronic Micelles: Effect of High-Frequency Ultrasound,” Journal of Controlled Release , vol. 84, no. 1, pp. 39-47, 2002.

• N. Rapoport, A. Marin, M. Muniruzzaman and D. A. Christensen, “Controlled Drug Delivery to Drug-Sensitive and Multidrug Resistant Cells: Effects of Pluronic Micelles and Ultrasound,” Chapter 7 in Advances in Controlled Drug Delivery, S.M. Dinh and P. Liu, eds, American Chemical Society Books, Washington, DC, 2003.

• S. Tolley,   H. Wang, R. Smith, D. Christensen and J. Herron, "Single-chain Polymorphism Analysis of Long QT Syndrome using Planar Waveguide Fluorescent Biosensors," Analytical Biochemistry , vol. 315, pp. 223-237, 2003.
• N.Y. Rapoport, D.A. Christensen, H.D. Fain, L. Barrows and Z. Gao, "Ultrasound-triggered drug targeting of tumors in vitro and in vivo," Ultrasonics , vol. 42, pp. 943-950, 2004.
• G.A. Husseini, M.A. Diaz de la Rosa, E.S. Richardson, D.A. Christensen and W.G. Pitt, "The Role of Cavitation in Acoustically Activated Drug Delivery," Journal of Controlled Release , vol. 107, pp. 253-261, 2005.
• R.D. Rabbitt, H.E. Ayliffe, D. Christensen, K. Parmarthy, C. Durney, S. Clifford and W.E. Brownell, "Evidence of Piezoelectric Resonance in Isolated Outer Hair Cells," Biophysical Journal , vol. 88, pp. 1-9, 2005.
• J.N. Herron, H-K. Wang, L. Tan, S.Z. Brown, A.H. Terry, S.E. Tolley, J.D. Durtschi, E.M. Simon, M.E. Astill, R.S. Smith and D.A. Christensen,  "Planar Waveguide Biosensors for Point-Of-Care Clinical and Molecular Diagnostics," Chapter 12 in Fluorescence Sensors and Biosensors (R. B. Thompson, ed.),  CRC Press Taylor & Francis Group, Boca Raton, FL, 2006.
• Husseini, Ghaleb A.: Diaz de la Rosa, Mario A.; Gabuji, Tasneem; Zeng, Yi; Christensen, Douglas A. and Pitt, William G., "Release of Doxorubicin from Unstabilized and Stabilized Micelles Under the Action of Ultrasound," Journal of Nanoscience and Nanotechnology , vol. 7, no. 3, pp. 1028-1033(6), March 2007.

Recent Patents

• “Diagnostic device and method,” US Patent No. 6,222,619 B1, April 24, 2001.
• “Oscillation apparatus and methods for multi-analyte homogeneous fluoro-immunoassays,” US Patent No. 6,242,267 B1, June 5, 2001.
• “System for determining analyte concentration,” US Patent 6,287,871 B1, September 11, 2001.
• “Apparatus and methods for multi-analyte homogeneous fluoro-immunoassays,” US Patent No. 6,316,274 B1, November 13, 2001.
• “Waveguide immunosensor with coating chemistry and providing enhanced sensitivity,” US Patent 6,340,598, January 22, 2002.
• “Integrated optic waveguide immunosensor,” US Patent No. 6,350,413 B1, February 26, 2002.
• “Lens and associatable flow cell,” US Patent No. 6,356,676 B1, March 12, 2002.
• “Ultrasonic Vascular Imaging System and Method of Blood Vessel Cannulation,” US Patent No. 6,755,789, June 29, 2004.
• "Composite Waveguide for Solid Phase Binding Assays," US Patent No. 6,911,344, June 28, 2005.
• "Apparatus and Methods for Multi-analyte Homogeneous Fluoroimmunoassays," US Patent No. 6,979,567, December 27, 2005.
• "Waveguide Immunosensor with Coating Chemistry and Providing Enhanced Sensitivity," US Patent No. 7,022,515, April 4, 2006.
• Plus Six European Patents (2002 and 2004)

Recent Conference Papers

• Norman Hu, Douglas A. Christensen, Amit K. Agrawal, John A. Hawkins, and Edward B. Clark, "Association of Aortic Arch Malformation Due to Altered Blood Flow Following Left Atrial Ligation in the Chick Embryo," Experimental Biology Conference, Washington D.C., April 16-18, 2004.
• Norman Hu, Douglas A. Christensen, Amit K. Agrawal, John A. Hawkins, and Edward B. Clark, "Dependence of Aortic Arch Morphogenesis on Intracardiac Blood Flow in the Chick Embryo," Weinstein Conference, Leiden, The Netherlands, May 13-16, 2004.
• D.A. Christensen, "A Freshman Major Lab Project Modeling the Human Cardiovascular System," Partnership for Educational Bioengineering Laboratories, Lansdowne, VA, June 4-6, 2004.
• D. A. Christensen and Kenneth W. Horch, "An Accelerated Dual-Degree BS/MS Program – Experience with the First Three Years," American Society for Engineering Education Annual Conference, Salt Lake City, Utah, June 20-23, 2004.
• D. A. Christensen, "Bringing an Integrative Modeling Experience to a Freshman Biomedical Engineering Course," American Society for Engineering Education Annual Conference, Salt Lake City, Utah, June 20-23, 2004.
• D.A. Christensen and K.W. Horch, "Experience with the First Three Years of an Accelerated Dual-Degree Program in Biomedical Engineering," Engineering in Medicine and Biology Society Annual Meeting, San Francisco, September 2004.
• Scott D. Brown, H.E. Ayliffe, Douglas Christensen, Greg Dittami, Sameera Dharia and Richard D. Rabbitt, "Electric Impedance Spectroscopy of Isolated Cells using Fringe-Field Surface Electrodes," BMES Annual Conference, Philadelphia, Oct. 2004.
• N. Rapoport, Z. Gao, P. Kamaev and D.A. Christensen, "Ultrasound-enhanced Localized Chemotherapy of Drug-sensitive and Multidrug Resistant Tumors," 5th International Symposium on Therapeutic Ultrasound, Boston, MA, October 27-29, 2005.
• G.A. Husseini, M.A. Diaz de la Rosa, E.S. Richardson, D.A. Christensen and W.G. Pitt, “Ultrasonic Drug Release from Micelles Correlates with Subharmonic Emission”, AIChE Annual Meeting, Cincinnati, OH, October 30-November 4, 2005.
• G.A. Husseini, M.A. Diaz de la Rosa, D.A. Christensen and W.G. Pitt, "The Role of Cavitation in Ultrasonic Release of Doxorubicin from Pluronic P105 Micelles," Society for Biomaterials 30th Annual Meeting, Memphis, TN, April 27-30, 2005.
• J.A. Hawkins, N. Hu, C. Beaumont, D.A. Christensen, A.K. Agrawal, and E.B. Clark, "Assessment of Blood Flow in Aortic Arch Arteries of the Neural Crest Ablated Chick Embryo," Pediatric Academic Societies' Meeting, Washington, DC, May 14-17, 2005.
• S. Dharia, H. Ayliffe, S. Brown, G. Dittami, A. Pungor, D.A. Christensen and R.D. Rabbitt, "Single Cell Electrophysiology on a Chip," 2005 Utah Mountainwest Biomedical Engineering Conference, Snowbird, UT, September 16-17, 2005 and also at the Biomedical Engineering Society (BMES) Annual Fall Meeting, Baltimore, MD, September 28-October 1, 2005.
• G.M. Dittami, H.E. Ayliffe, P. Kiser, D.A. Christensen, S. Brown,   S. Dahria and R.D. Rabbitt, "Hydrogel-Actuated, Impedimetric Biochemical Sensors," 2005 Utah Mountainwest Biomedical Engineering Conference, Snowbird, UT, September 16-17, 2005, and also at the Biomedical Engineering Society (BMES) Annual Fall Meeting, Baltimore, MD, September 28-October1, 2005.
• D.A. Christensen, "An Accelerated Dual-Degree BS/MS Program--Experience with the First Three Years,"   NSF Engineering and Computing Education Grantee Meeting, Washington, DC, February 16-18, 2005.
• D.A. Christensen, "Bringing an Integrative Modeling Experience to a Freshman Biomedical Engineering Course," Whitaker Biomedical Engineering Education Summit,   Arlington, VA, February 2005.
• K. Horch and D. Christensen, "Early Career Guidance for Biomedical Engineering Premajors," Whitaker Biomedical Engineering Education Summit,   Arlington, VA, February 2005.
• Douglas Christensen and Aborn Chao, "A Pulsed Schlieren System for Visualizing Beams from Phased-Array HIFU Applicators," Intern. Symp. Therapeutic Ultrasound, Oxford, UK, Aug. 2006.   Also presented at Mountain West Biomedical Engineering Conference, Snowbird, Utah, Sept. 2006.
• Douglas A. Christensen, Lyndon Tan, Jacob D. Durtschi, Samuel Tolley, Hsu-Kun Wang, Alan H. Terry, Mark E. Astill, Richard S. Smith and James N. Herron, "Rapid Clinical and Molecular Diagnostic of Heart Disease Using Biosensor Technology," Improving Health Care Accessibility Workshop, sponsored by NIBIB, NHLBI and NSF, Arlington, VA, April 11-12, 2006.
• S. Dharia, J. Braithwaite, C. King, G. Dittami, H. Ayliffe, A. Pungor, D.A. Christensen and R.D. Rabbitt, "Micro-Domain Single Cell Electrophysiology," BMES Annual Meeting, Chicago, Illinois, October 12, 2006.
• S. Dharia, H.E. Ayliffe, J. Braiwaith, C. King, S. Brown, G. Dittami, A. Pungor, D. Christensen and R.D. Rabbitt, "Towards Micro-Electric Impedance Tomography," Biophysical Society Annual Meeting, Salt Lake City, UT, Feb. 20, 2006.