EUROMET PROJECT
FINAL REPORT
1. Ref. No.: 671 / 2. Subject Field: acoustics, ultrasound and vibration
3.Type of collaboration:
Research and Development project between Europen and Australian partners
4A.Partners: TNO Prevention and Health (TNO-PG) (NL)
(institutions)National Physical Laboratory (NPL) (UK)
Physikalisch-Technische Bundesanstalt (PTB) (DE)
CSIRO (Australia) / 4B.CEC funded? X
5.Participating countries: NL, UK, DE, AUS
6.Title: Development of transfer standard devices for ensuring the accurate calibration of ultrasonic therapy machines in clinical use”.
7.Progress:
Therapeutic ultrasound equipment is widely used upon patients. It can be estimated from a number of surveys that unfortunately 70% of the devices used do not comply with the relevant standard for accuracy in output which states: actual output shall be within 20% of that indicated on the device. Extreme cases have often been reported where machines in use are delivering effectively no ultrasound or up to many factors greater than the amount indicated. This creates patient injury problems as well as mistreatment. To address this problem the project plans to:
  • Develop an ultrasound power standard, presently being exclusively developed for European national standards laboratories, into a robust and portable form. The power standard would include a Cavitation Detector to determine the onset of adverse measuring conditions. The power standard would be suitable for conducting in-the-field proficiency testing of small companies, hospitals and manufacturers undertaking routine ultrasound therapy machine testing.
  • Produce a number of advisory publications and international standards for physiotherapists and those testing ultrasound therapy machines.
7a.Project Results
The project resulted in the following deliverables
  • Four sets of transducers to be used in connection with the Portable Power Standard and Cavitation Detector.
  • Four prototype Portable Power Standards suitable for the proficiency testing of commercial testers of ultrasound therapy machines "in-the-field".
  • Four prototypes Cavitation Detectors to determine the onset of cavitation during the use of the Portable Power Standard or for use as a general tool for establishing the onset of cavitation during power measurements.
  • Advisory publications in conjunction with the professional associations of interested parties and IEC standards which notify clinical users and commercial testers of the mechanism for obtaining traceability and the key documentation to seek.
7c The Publications:
  • This project has was funded by the 5th Framework programme. (EC-Contract no. G6RD-CT-2001-00600)
  • EC report: Development of transfer standard devices for ensuring the accurate calibration of ultrasonic therapy machines in clinical use; EU contract G6RD-CT-2001-00600.
  • Rob T. Hekkenberg, Adrian Richards, Klaus Beissner, Bajram Zeqiri, Robert A. Bezemer, Mark Hodnett, Glen Prout and Chris Cantrall, “Transfer standard device to improve the traceable calibration of physiotherapy ultrasound machines”, UMB, Volume 32, Issue 9, September 2006, Pages 1423-1429.
  • R. T. Hekkenberg et al.: Development of transfer standard devices for ensuring ... J. Physics. Conf. Series 1 (2004), 99-104.
  • R. T. Hekkenberg et al.: Development of transfer standard devices for ensuring ... J. Physics. Conf. Series 1 (2004), 99-104.
  • M. Hodnett, B. Zeqiri: A detector for monitoring the on-set of cavitation... J. Physics. Conf. Series 1 (2004), 112-117
  • K. Beissner, “Tragbares Leistungsnormal für die Ultraschall-Physiotherapie”, Development of transfer standard devices for ensuring the accurate calibration of ultrasonic therapy machines in clinical use.
  • Final Newsletter on EC projectTransfer standard device for ensuring the accurate calibrationof ultrasonic therapy machines in clinical use., 14 June 2005 (included)

8.Coordinator’s name: R.T. Hekkenberg
Address:TNO-Quality of Life, Quality in Health Care
Wassenaarseweg 56, 2333 AL, Leiden, The Netherlands
P.O.Box 2215, 2301 CE, Leiden, The Netherlands
Telephone: +31 71 518 1242 Telefax: +31 71 518 1902 E-mail:
9.: Completion date:
31 – 05- 2005 / 10. Proposer´s signature
Rob Hekkenberg / 11. Date: 20-10-2006

Notes for completion of the form overleaf

Final Newsletter on EC project

Transfer standard device for ensuring the accurate calibration

of ultrasonic therapy machines in clinical use.

PORTABLE POWER STANDARD NOW AVAILABLE

INTRODUCTION. The Portable Power Standard that has been developed in a European collaborative project is now ready for use. It consists of a Driver, five transducers (treatment heads) and a Cavitation Detector. The Portable Power Standard would be suitable for conducting in-the-field proficiency testing of small companies, hospitals and manufacturers undertaking routine ultrasound physio-therapy machine testing. It can also be used for tutorial and calibration purposes. Those active in this field are encouraged to use the tool to provide for a traceable calibration of their equipment.

The Driver unit contains an electrical signal generator and programmable power amplifier to drive the ultrasound transducers. The unit can drive the full set of transducers described. The internal programmer stores signals from the Cavitation Detector and the temperature probe to measure the water bath temperature.

The Cavitation Detector’s purpose is to alert the user to the presence of cavitation activity occurring, which may then affect the accuracy of power measurements. Cavitation bubbles produced and excited at 1 MHz will radiate a broad spectrum of acoustic radiation into the water. This is measured by the sensor that transfers the ultrasonic signal into an RF voltage. So, the Cavitation Detector is essentially an RF Voltmeter with a very narrow bandwidth tuned to a nominal centre frequency of 1,5MHz.

Five transducers comprise the set used with the Portable Power Standard, and these are representative of treatment heads used in clinical practice. The set includes one transducer exhibiting an unusual output as a negative control.

Nominal specifications of transducers used in the Portable Power Standard /
Ultrasound transducers to be used
Transducer / Frequency (nom) / Effective radiating area / Beamtype / ka / Power range
(MHz) / Aer (cm2) / (W)
1 / 3,0 / 0,4 / collimating / 43 / 0,1 – 3,0
2 / 3,0 / 3,4 / collimating / 72 / 0,1 – 15,0
3 / 1,0 / 0,9 / diverging / 22 / 0,1 – 3,0
4 / 1,0 / 3,4 / collimating / 43 / 0,1 – 15,0
5 / 3,1 / 0,8 / collimating / 57 / 0,1 – 3,0
Contact details of institutes that offer the Portable Power Standard on a short term rental basis are:
In the Netherlands: TNO Quality of Life, Zernikedreef 9, 2333 CK, Leiden, The Netherlands,
 +31 (71) 518 1242, Email:
In Germany: Physikalisch-Technische Bundesanstalt, PTB, Bundesallee 100, D-38116, Braunschweig, Germany
 +49 (531) 592 1431, Email:
In the United Kingdom: National Physical Laboratory, NPL, Hampton Rd, Teddington, TW11 0LW, United Kingdom
 +44 (208) 943 6365, Email:

EC Research programme: Competitive and Sustainable Growth,Project Reference: G6RD-CT-2001-00600

Printing date: 14 June 2005