Patent ID: 8147411

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 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 an antenna and electrically coupled to the oscillator to receive a fourth electrical signal based upon the first electrical signal and to transmit through the antenna an unmixed electromagnetic signal based upon the fourth electrical signal, the transmitter assembly electrically coupled to the receive transducer to receive a third electrical signal based upon the second electrical signal to transmit through the antenna an electromagnetic signal based upon the third electrical signal; and a first frequency selective filter coupled between the oscillator and the transmitter assembly, and a second frequency selective filter coupled between the receive transducer and the transmitter assembly.