Cardiac Surgeon Bill Cohn Teaching at Harvard Medical School

Bill Cohn teaches a class at Harvard Medical School in Boston. Cohn operates on beating hearts without a heart-lung bypass machine, and believes that patients recover faster when their surgery can be done "off pump." This photo was taken from the back of a classroom during a lecture, without flash, using only the natural light in the room. An excellent article about Cohn appeared in the New Yorker.