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
Recommended Actions
- Prepare comprehensive device description including all technical specifications
- Conduct required testing:
- Electrical safety and EMC
- Software validation
- Biocompatibility
- Performance testing for output parameters
- Develop complete labeling package including:
- Device and component identification
- Operating instructions
- Safety information
- Cleaning/reprocessing instructions
- Prepare 510(k) submission including:
- Detailed predicate comparison
- Test reports and validation data
- Risk analysis
- Complete labeling
- Ensure compliance with:
- Maximum treatment time limit
- Output intensity limits
- Safety requirements for patient contact
- Software documentation requirements
- Validate reprocessing procedures if device is reusable
- 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
- Wireless technology considerations if applicable
- Reprocessing validation if reusable device
Relevant Guidances
- Content of Premarket Submissions for Device Software Functions
- Cybersecurity in Medical Devices: Design, Implementation, and Premarket Submissions
- Use of ISO 10993-1 for Biological Evaluation and Testing of Medical Devices
- Reprocessing Instructions for Reusable Medical Devices and Non-Sterile Single-Use Devices - Development and Validation
- Electromagnetic Compatibility for Medical Devices and Accessories: Testing, Documentation, and Labeling Requirements
Related references and norms
- 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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