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Ultrasonic Diathermy (Physiotherapy) Devices - Technical and Safety Requirements for 510k Submissions

This guidance applies to ultrasonic diathermy (physiotherapy) devices regulated under 21 CFR 890.5300(a) that: - Apply therapeutic deep heat for medical conditions like pain relief, muscle spasms, and joint contractures - Operate at frequencies above 20 kHz - Use a single plane circular transducer per treatment head - Produce non-convergent beams perpendicular to the treatment head face

  1. Prepare comprehensive device description including all technical specifications
  2. Conduct required testing:
    • Electrical safety and EMC
    • Software validation
    • Biocompatibility
    • Performance testing for output parameters
  3. Develop complete labeling package including:
    • Device and component identification
    • Operating instructions
    • Safety information
    • Cleaning/reprocessing instructions
  4. Prepare 510(k) submission including:
    • Detailed predicate comparison
    • Test reports and validation data
    • Risk analysis
    • Complete labeling
  5. Ensure compliance with:
    • Maximum treatment time limit
    • Output intensity limits
    • Safety requirements for patient contact
    • Software documentation requirements
  6. Validate reprocessing procedures if device is reusable
  7. Implement cybersecurity measures if applicable

Key Considerations

Non-clinical testing

  • Electrical safety and EMC testing according to ANSI/AAMI ES60601-1 and IEC 60601-1-2
  • Performance testing to demonstrate output power and effective intensity specifications
  • Validation of timer accuracy (±10% of setting)
  • Validation of unwanted ultrasound radiation (<100 mW/cm2)
  • Temperature rise characterization

Software

  • Documentation level should be “Enhanced” (formerly “Major” level of concern)
  • Full software description and validation documentation required
  • Cybersecurity considerations if applicable

Cybersecurity

  • Required if device includes wireless capabilities or networked features
  • Address data integrity, coexistence, security aspects

Labelling

  • Detailed device description including specifications
  • Contraindications, warnings and precautions
  • Operating instructions
  • Cleaning/reprocessing instructions
  • Device and treatment head identification/specifications
  • Control labeling

Biocompatibility

  • Testing for cytotoxicity, sensitization and irritation required
  • Evaluation of transmission media (coupling gel)

Safety

  • Maximum treatment time not exceeding 30 minutes
  • Maximum effective intensity not exceeding 3 W/cm2
  • Beam non-uniformity ratio not exceeding 8
  • Moving treatment head requirement to avoid burns

Other considerations

  • IEC 61689: Ultrasonics - Physiotherapy systems - Field specifications and methods of measurement in the frequency range 0,5 MHz to 5 MHz
  • IEC 60601-2-5: Medical electrical equipment - Part 2-5: Particular requirements for the basic safety and essential performance of ultrasonic physiotherapy equipment
  • ANSI/AAMI ES60601-1: Medical electrical equipment - Part 1: General requirements for basic safety and essential performance
  • ISO 10993-1: Biological evaluation of medical devices - Part 1: Evaluation and testing within a risk management process

Original guidance

  • Ultrasonic Diathermy (Physiotherapy) Devices - Technical and Safety Requirements for 510k Submissions
  • HTML / PDF
  • Issue date: 2023-02-21
  • Last changed date: 2023-02-21
  • Status: FINAL
  • Official FDA topics: Medical Devices, 510(k), Premarket, Physical Medicine
  • ReguVirta summary file ID: 07ec8fa3d9c1d889c85a2889dd6f5bac
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