Public defence: Thong Tuan Huynh

Thong Tuan Huynh will defend his PhD degree in Applied Micro and Nano Technology. The thesis investigates potential of the sources of undesired nonlinear effects in medical ultrasound probes, as this may degrade the quality of medical ultrasound images.

15 Jan

Practical information

  • Date: 15 January 2026
  • Time: 10.00 - 15.00
  • Location: Vestfold, Auditorium A1-36 Horten
  • Download calendar file

    • Link to digital participation (Zoom).

    Programme

    10:15 Trial Lecture: "Will AI make the radiologist unemployed"

    12:15 Public defence: Nonlinearity in medical ultrasound probes

    Assessment committee

    • First opponent: Professor Nico de Jong, Erasmus University Medical Center, Netherlands.
    • Second opponent: Professor Frank Melandsø, UiT The Arctic University of Norway
    • Administrator: Førsteamanuensis Anna Pachol, University of South-Eastern Norway

    Supervisors

    • Principal supervisor: Professor Lars Hoff, University of South-Eastern Norway
    • Co-supervisor: Senior Research and Development Engineer Trym Haakon Eggen, GE Vingmed Ultrasound
Any questions?

Thong Tuan Huynh is defending his dissertation for the degree philosophiae doctor (PhD) at the University of South-Eastern Norway.Disputant, doktorgradsstudent

The doctoral work has been carried out at the Faculty of Technology, Natural Sciences and Maritime Sciences.

You are invited to follow the trial lecture and the public defence.

Summary

Utilizing the nonlinear properties of acoustic waves is an emerging field with great potential. This is especially true for medical ultrasound imaging but is also seen in other fields of acoustics. The most important example so far was the introduction of ‘second harmonic imaging’, a technique that revolutionised the quality of medical ultrasound images when it became widely adopted around 2010 and remains extensively used today.

Second harmonic imaging requires precise control of the transmitted ultrasound pulses, which must be strictly free of harmonic distortion. This PhD thesis investigated potential sources of such nonlinear distortion in a medical ultrasound system. The study identified the ultrasound transducer as the dominant source of nonlinearity, while electronic amplifiers, cables and electric matching networks were found to have negligible influence. A subsequent comparative analysis studied four medical ultrasound transducers using different piezoelectric materials and operating at different resonance modes. This study revealed that nonlinearities associated with the internal mechanical motion were the primary contributor compared to those arising from purely electric effects.

Beyond these specific findings, this work has introduced new measurement methodologies that offer a systematic approach for identifying nonlinear mechanisms in ultrasound systems.

The new insights presented in this thesis will be of use for scientists and engineers developing the next generations of medical ultrasound systems, where innovative use of nonlinear acoustics is expected to improve medical diagnosis and therapy beyond current capabilities.