Patent ID: 8092389

Claim:
For implantation into a biological structure having a fluid flow of an average velocity with surfaces traveling with substantially the average velocity in the fluid flow through the biological structure, a system comprising: an oscillator configured to generate a first electrical signal having a first frequency; a transmit transducer electrically coupled to the oscillator and configured to transmit an acoustic beam based upon the first electrical signal, the transmit transducer configured within the system to be positioned to transmit the acoustic beam into the fluid flow when the system is implanted into the biological structure; a receive transducer configured within the system to receive a reflected portion of the acoustic beam reflected off of a portion of the surfaces traveling in the fluid flow and to produce a second electrical signal based upon the portion of the acoustic beam received by the receive transducer; a transmitter assembly comprising a first antenna and electrically coupled to the oscillator and configured to transmit through the antenna an unmixed electromagnetic signal based upon the first electrical signal; a first frequency selective filter electrically coupled between the receive transducer and a mixer, the mixer configured to receive a third electrical signal having a selectively filtered frequency of the second electrical signal, a second frequency selective filter electrically coupled between the oscillator and the mixer, the mixer configured to receive a fourth electrical signal having a selectively filtered frequency of the first electrical signal, the mixer configured to generate a fifth electrical signal based upon the third electrical signal and the fourth electrical signal received by the mixer; and wherein the transmitter assembly is electrically coupled to the mixer and configured to transmit through a second antenna an electromagnetic signal based upon the fifth electrical signal.