Overview
IEC 61847:1998 defines the measurement and declaration of the basic non-thermal output characteristics of ultrasonic surgical systems. It applies to ultrasonic surgical units operating in the 20 kHz to 60 kHz range that deliver fragmentation or cutting of human tissue via a purpose-designed waveguide (applicator tip). The standard specifies which output parameters manufacturers should declare and describes measurement methods so results are comparable and reproducible.
Key topics and technical requirements
- Applicable systems: Devices that transmit acoustic waves through a waveguide to the surgical site and are used for tissue fragmentation/cutting. Exclusions include extracorporeal lithotripsy, hyperthermia systems, and devices outside the monopole tip model.
- Primary measured parameters:
- Primary tip vibration excursion (peak-to-peak displacement measured ≤1 mm from the distal end)
- Secondary tip vibration excursion and tip vibration frequency
- Drive frequency and duty cycle (for modulated systems)
- Quiescent and maximum electrical power and power reserve index (ratio of max to quiescent power)
- Output acoustic power (measured calorimetrically in water) and derived output acoustic power (from hydrophone measurements)
- Primary and secondary acoustic output areas and directivity pattern
- Tip excursion modulation and pulse-duration definitions for pulsed/modulated drives
- Measurement methods: Standard references methods and conditions (including hydrophone and calorimetric techniques) are described so technically qualified personnel can perform consistent tests. Measurement accuracy is expressed at the 95% confidence level.
- Declaration: Specifies which characteristics manufacturers should report to allow device comparison and application of ALARA (as low as reasonably achievable) principles.
Practical applications and users
Who uses IEC 61847:
- Medical device manufacturers - to characterize and declare ultrasonic output for product documentation and regulatory submissions.
- Test laboratories / calibration facilities - to perform standardized acoustic and electrical measurements.
- Regulatory agencies and notified bodies - to assess declared device output characteristics.
- Clinical engineers and procurement teams - to compare devices based on standardized metrics (e.g., tip excursion, acoustic power, power reserve).
- R&D teams - for design validation and benchmarking of transducer/handpiece combinations.
Practical benefits:
- Enables consistent comparison of acoustic power, tip displacement, and directivity across devices.
- Supports risk management and selection of appropriate devices for sensitive surgical sites (e.g., ophthalmology, neurosurgery).
Related standards
Keywords: IEC 61847, ultrasonic surgical systems, output characteristics, acoustic power, tip vibration excursion, hydrophone, calorimetric measurement, power reserve index.