Transmission Ultrasound

Overview
Through-transmission ultrasound, or transmission ultrasound for short, is the method in which one transducer emits sound waves, and another transducer not part of the transmitting array receives the signals. This is different from conventional ultrasound where the echos are captured from a 180 degree reflection, in the fact that the wave travels through a medium and is picked up on the other side.

 

The Sonix systems can be setup to perform transmission ultrasound with the following setup:
 * One Sonix RP or SonixTOUCH Research system
 * Two of the same model transducers (i.e. L14-5/38)
 * Access to the Texo SDK

Implementation

 * Both transducers share the same sequencer for transmit and receive
 * The sequencer is set to start the transmit at one end and start the receive at the other end
 * The transmits and receives are aligned by flipping one of the transducers while facing each other
 * Half of the transducers are used for imaging and the other halves are covered to block unwanted transmits

The following is some pseudo-code that would run a Texo sequence for transmission ultrasound:

// assume probes plugged into top and middle ports texo->activateProbeConnector(0) texo->forceConnector(2)

for (i = 0; i < numElements / 2; i++) { tx.centerElement = (i * 10) + 5 rx.centerElement = ((numElements - i -1) * 10) + 5 texo->addLine(tx, rx) }

 

During the experimental setup, the transducers should be placed directly facing each other in a water bath or with a medium in between, similar to the diagram below.

 

Results
Below are some results from a simple experiment in a water bath with two linear transducers.