Acoustical Society of America
R. Bruce Lindsay Award - 2004

Michael R. Bailey

MICHAEL ROLLINS BAILEY was born on 31 May 1969 to David and Patricia Bailey in Bethesda Naval Hospital, where David worked at NIH as a commissioned officer in the Surgeon General's office.

Mike's interest in science was already evident in elementary school. Given the opportunity to dissect a fetal pig. Mike made notes of all the organs, cleaned the skeleton, and kept the little pig skull in his room. After attending Westminster High School in Simsbury, Connecticut, where he was class valedictorian and received awards in science and math, Mike entered Yale in 1987.

Mike thrived at Yale. He rowed for the crew team, trained as a long distance runner, and, oh yes, attended class as a Mechanical Engineering student. Meeting and working with Bob Apfel and his students, especially Christy and Scott Holland, had a big influence on Mike. They helped him acquire an appetite for acoustics, especially medical ultrasonics, and also identified David Blackstock's lab at Applied Research Laboratories (ARL), University of Texas at Austin, as a good place for graduate studies.

At Texas Mike met his future wife Tricia when she was a senior mechanical engineering student. Tricia likes to point out that, while she had 60 engineering credits at Texas, for his ME degree at Yale Mike had only 20 engineering credits—but he was familiar with British literature and had a great vocabulary!

Although things did not go swimmingly at first at Texas, Mike showed his ingenuity when, for his Master's thesis, he turned a Blackstock homework problem into an experimental study of diffraction by a jagged edge. In a summer spent with Ed Carstensen's group at the University of Rochester, he applied his knowledge of jagged-edge diffraction to a medical ultrasound problem.

Mike's doctoral research on lithotripsy (the use of shock waves to break kidney stones) developed from a question Larry Crum posed during a visit to Austin: Can cavitation be enhanced by using two pulses, the first one negative to initiate cavitation, the second one positive, time to drive the cavitation bubble into more intense collapse? The typical lithotripsy pulse, produced when a rigid ellipsoidal reflector focuses an underwater shock wave emitted by an electric spark, is a very strong positive spike followed by a long, relatively weak negative tail. The strong positive spike could be the second pulse in the two-pulse sequence. But how to produce the negative pulse? Mike's solution was to machine a pressure-release ellipsoidal reflector out of polyurethane (pressure release material). The ideas was to flip the polarity when reflection of the spark-generated pulse occurred. Although the design worked, the increased intensity of the cavitation collapse was not all that had been hoped for. Nevertheless, the investigation led to the realization that a two-pulse lithotripter could be used to control the pulse that hits the stone. A summer spent with Larry Crum's group at Applied Physics Laboratory (APL), University of Washington, where he rekindled the collaboration with Robin Cleveland he had had at Texas, opened up applications of the two-lithotripter design. After finishing his doctorate at Texas (1997), Mike returned to Larry's group as a postdoc, where he worked on both the reversed-waveform lithotripter (pressure release reflector) and the dual-pulse lithotripter (two separate pulses timed to control the waveform at the stone).

At APL he soon expanded his collaborations and began work with Andy Evan, Jim McAteer, and their colleagues at Indiana University School of Medicine (Indianapolis) on studies to determine how shock waves cause tissue damage. At last, Mike had returned to his early fascination with pig anatomy! Mike's work with the Indianapolis team has produced an impressive list of first-rate publications on the mechanisms of stone breakage and tissue injury in shock wave lithotripsy.

At Indianapolis a few experiments on pigs showed that Mike's reversed-waveform lithotripter caused absolutely no damage to the pig's kidney. He had just invented the world's safest lithotripter! He then tested it for stone breakage and discovered another important fact: he had just invented the world's most ineffective lithotripter. The reversed-waveform lithotripter couldn't even crack the stone! So Mike discovered how science often works: unexpected results almost always lead to advanced knowledge. The fact that the reversed-waveform lithotripter suppressed cavitation entirely implied that cavitation is a dominant mechanism in both stone comminution and kidney damage. Mike's concept of dual-pulse lithotripsy has recently been adopted by the lithotripter industry, and the latest, most innovative shock wave devices on the market are dual-pulse machines.

As if Mike and Tricia were not already busy enough, they purchased a 1906 home in Seattle that looked its age. Living in the scary cellar, they gutted the house, reroofed it, put in all new plumbing and wiring, redid the floors, walls, etc., all the while reading "how to books" and taking Home Depot courses.

Our admiration for Mike the person is boundless. He is easygoing and a perfect team player. Very talented and creative, he is also one of the most modest, selfless, and giving individuals we know. Mike puts others first, in both personal and professional interactions. He could easily, legitimately, have placed his name as first author on many of his publications. Instead he helped a student or a visiting scientist get the recognition. At APL Mike is known as "the guy with all the students." Likeable, willing, and talented, he attracts an impressive number of students, particularly undergraduates. So noteworthy have been his contributions to student education that APL Director Bob Spindel gave Mike the "Director's Award" this past year. Given his short tenure at APL, this was singular recognition of how highly Mike is regarded by his colleagues.

Besides his technical achievements, Mike has also made noteworthy contributions to ASA. An active member of the Society since his graduate student days, he has promoted its scientific and educational mission. For example, at the last ASA meeting in Austin, Mike was co-author of nine different oral presentations, and he organized and co-chaired three different sessions sponsored by the Technical Committee on Biomedical Ultrasound/Bioresponse to Vibration, including a well-attended Friday afternoon session (interrupted by the collapse of a water-soaked ceiling in the session room) that ran well past the 5 p.m. scheduled ending.

Today we add Mike Bailey's name to that illustrious list of distinguished young scientists who have earned our acclaim as Lindsay Award winners. In doing so we continue to ensure that our Society will have a bright future indeed.

DAVID T. BLACKSTOCK

LAWRENCE A CRUM

JAMES A. MCATEER