CHAPTER 2 F LOW S ENSORS FOR L IQUIDS M. Mischi and J. A. Blom Department of Electrical Engineering Eindhoven University of Technology, Eindhoven, The Netherlands 2.1. INTRODUCTION Flow is a general word addressing a variety of realities. This is particularly true for the flow of liquids in a biomedical context. In the human body, blood flow is of major importance for the characteriza- tion of the cardiovascular system, but the flow of other fluids, such as urine, must also be considered.