Schema Transit Time Messung

How does the Transit-Time Ultrasound Method work?

em-tec offers many different flow measurement systems which are based on the transit-time ultrasound principle:

The SonoTT Vascular Probe surrounds the blood vessel, generating an ultrasound field across the whole vessel diameter. Ultrasonic impulses are sent from one piezo crystal to another via the reflector, with the crystals acting alternately as transmitters and receivers. The transit time taken by each impulse is determined. The differences in transit times taken by the impulses flowing up-stream and the ones flowing downstream are proportional to the flow rate. The measurement principle of em-tec’s Clamp-on Transducers for tubing systems is also based on the transit-time method. Four piezo crystals arranged in an X configuration scan the fluid flow by ultrasonic transmission, calculating the differences of upstream and downstream transit times.

Technology / Applications

Examples of applications for flow measurement on blood vessels:

  • Cardiovascular Surgery: Measurement of bypass grafts, Detection of stenosis
  • Vascular Surgery: Detection of arteriovenous fistulas during in-situ bypass surgeries, Intraoperative graft patency control of distal-femorotibial bypass grafts (CABG), Functional Assessment of Dialysis Shunts
  • Transplant Surgery: Measurement of perfusion during liver and kidney transplant

Extracorporeal flow measurements:

  • Extracorporeal Membrane Oxygenation (ECMO)

The use of clinical procedures and techniques is the sole responsibility of the physician.

Examples for use in bio-process or in any other processes with strict hygiene requirements:

  • Bioreactors
  • Fermenter
  • Sterile filling processes
  • Pump feedback control loops
  • Tagnential Flow Filtration
  • Chromatography
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Partners in Science

We place great importance on our partnerships with world-renowned research institutes and universities. Our network is the result of many years of cooperation in which we have created symbioses with scientific collaborators.

We also support valuable research in the field of medical science, an integral part of the launch of new medical devices.

Take advantage of our expertise when developing your next new product!