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  • 1.  Wearable vibration therapy: Class I (rule 13) or Class IIa (rule 9)

    This message was posted by a user wishing to remain anonymous
    Posted 17-Feb-2022 16:01
    This message was posted by a user wishing to remain anonymous

    Hi,

    I have a EU classification question regarding a local vibration therapy device (wearable, worn as a garment) that helps for muscle pain management and recovery. This device is active (battery powered), therefore EU MDR Rules 9-13 apply.

    I'm debating whether vibration therapy should be classified as "administering / exchanging energy" (EU MDR Rule 9 --> Class IIa) or if it should be classified under EU MDR Rule 13 --> Class I (all other active devices).

    When looking at MDCG 2021-24, none of the examples provided under Rule 9 seem to fit:
    • Electrical and/or magnetic and electromagnetic energy:
      • muscle stimulators
      • external bone growth stimulators
      • TENS devices
    • Mechanical energy:
      • powered dermatomes
      • powered drills
      • dental hand pieces
    • Kinetic energy:
      • lung ventilators

    Is this device a Class I (rule 13) or Class IIa (rule 9)?

    Thanks for your help.


  • 2.  RE: Wearable vibration therapy: Class I (rule 13) or Class IIa (rule 9)

    Posted 18-Feb-2022 08:02
    Hello Anon,

    At first view of the product, it most likely would fall under Rule 9 because 'administering / exchanging energy' is now being viewed fairly broadly including example of your product.  With that said, this can be quite subjective with different opinions by regulatory professionals and also Notified Bodies.  Ultimately, a Component Authority / EU Commission can make a classification determination, but this can be a long process.  You can always approach a Notified Body to get feedback, but again this can be subjective as well.  You are right to review the MDCG guidance document, though while not addressing your device specifically it gives an idea for the type of devices, e.g. magnetic fields.  So if vibration considered energy?  Maybe going back to physics to determine, whichever classification is determined recommend having a classification rationale contained in the Technical Documentation.

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    Richard Vincins ASQ-CQA, MTOPRA, RAC
    Vice President Global Regulatory Affairs
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    Original Message


  • 3.  RE: Wearable vibration therapy: Class I (rule 13) or Class IIa (rule 9)

    Posted 18-Feb-2022 10:16
    Hello - 

    Either way, you will need to provide the rationale for your choice in your technical documentation.  Plus, your detailed device description will need to address the principles of operation of the device and its mode of action. At first glance with the description provided, I would be challenged to say that your device falls under Rule 13.  The examples provided for Rule 9 (or any others) are not intended to be exhaustive, and my initial reaction is that a battery operated device that generates vibrations to help with muscle pain management and recovery easily falls within the same category as muscle stimulators and TENS devices, which have very similar intended uses in pain management/recovery.  If your intended use/purpose is that similar, you would have to rely on being able to demonstrate that your principles of operation and/or mode of action are dramatically different than other "electrical and/or magnetic and electromagnetic energy powered active devices" to get to Rule 13.  Good luck!

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    Robin Haden RAC
    Sr. Regulatory Affairs Specialist
    New Hill NC
    United States
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    Original Message


  • 4.  RE: Wearable vibration therapy: Class I (rule 13) or Class IIa (rule 9)

    Posted 20-Feb-2022 02:53
    Hi
    To my understanding this device is a active therapeutic device, see definitions in article 2 (4) and Annex VIII 2.4. It exchanges mechanical energy with the patient for treatment or alleviation of an illness, injury or disability.  
    Therefore rule 9 applies . 
    When looking into the MDCG guidance 2021-24 a few examples where the device exchanges energy on a purly mechnical way can be found:
    - Ultrasound: equipment for physiotherapy 
    - lithotriptors, surgical ultrasound devices (class IIb)
    The ultrasound example is probably most suitable. It's just a lower frequency. 

    Best regards,
    Raimund


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    Raimund Gleixner
    München
    Germany
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    Original Message


  • 5.  RE: Wearable vibration therapy: Class I (rule 13) or Class IIa (rule 9)

    Posted 20-Feb-2022 03:10
    If the device administers energy by means of vibration that is kinetic energy which the device conveys by means of the vibrational motion and kinetic impact on the patient's body. Hard to argue your way out of that being administering kinectic energy if you ask me.

    But you never know with notified bodies and authorities, they can be subject to very resilient confirmation bias trumping actual scientific state of art. I've had competent authorities argue that binding by means of Van der Waals forces is a pharmacological effect so you never know if you might be lucky (or unlucky). Before you ask the question, better be sure to know what direction they are leaning because you might up in a place where you don't want to be (e.g. pharmacological Van der Waals binding) and then unable to extract yourself from it.

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    Erik Vollebregt
    Partner
    Amsterdam
    Netherlands
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    Original Message


  • 6.  RE: Wearable vibration therapy: Class I (rule 13) or Class IIa (rule 9)

    Posted 21-Feb-2022 10:25
    Good Day,

    I have to say, I am by no means an expert, but I can give you the rationale I used for our device and just replied to a classification question on our MDR application, and I believe my rationale was accepted.  

    Based on your description, I would argue this device, even though has a power supply is NOT considered an active device.  Per the definition in the MDCG guidance document

    "Active device means any device, the operation of which depends on a source of energy other than that generated by the human body for that purpose, or by gravity, and which acts by changing the density of or converting that energy. Devices intended to transmit energy, substances or other elements between an active device and the patient, without any significant change, shall not be deemed to be active devices"  

    It sounds as if, even though your device emits energy there is no exchange or significant change- but that would be the manufacturer to determine. However it doesn't appear to be that type of device.  

    Therefore, I think Rule 1, would apply.  Its not active and not invasive.  Class I.

    Our device sends electrical stimulas to the toungue, so I had to use Rule 4 class IIa is it enters a mucous membrane, but still was not considered active. I hope that helps.

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    Julie Popp
    Monona WI
    United States
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    Original Message


  • 7.  RE: Wearable vibration therapy: Class I (rule 13) or Class IIa (rule 9)

    Posted 21-Feb-2022 11:45
    Interesting, but a pretty radical approach because it assumes that there is no significant change in the energy transmitted for this mode of action (vibration on skin), as is explained one page further in the MDCG 2021-24 guidance:

    "The concept of significant change for energy includes changes in the nature, level and density of energy (see Rule 9). This means that for instance an electrode is not considered an active device under this classification system as long as the energy input is intended to be the same as the energy output. Resistance in a wire that causes minor changes between input and output cannot be considered to constitute 'significant change'. However, electrodes used in electrosurgery for cutting tissues or cauterisation are active devices because their operation depends on energy provided by a generator and their action is achieved by conversion of energy at the interface between the device and the tissue or in the tissue." (MDCG 2021-24, p. 11)

    Transmission of energy by means of kinetic impact on the body (vibration on skin) is by its very nature rather inefficient (very inelastic collision from a physics perspective) so I would really not expect this argument to hold up for a class I rationale. That would only work if you could argue that the kinetic impact on the body would comprise a nearly elastic collision (much more efficient transmission of energy) - brick on skull maybe :-) 


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    Erik Vollebregt
    Partner
    Amsterdam
    Netherlands
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    Original Message


  • 8.  RE: Wearable vibration therapy: Class I (rule 13) or Class IIa (rule 9)

    Posted 21-Feb-2022 11:07
    If I had to bet I'd say rule 9. Additionally, after comparing the examples for both rules in the MDCG guidance 2021-24, I think your device is more like those in rule 9.

    It's far from a guarantee but you could start by looking at competitor devices and their labelling - does their CE mark include a notified body number? 

    If you find a NB number, it's not a class I device (unless it's also sterile or measuring). 

    Just check that competitors are making similar intended use claims, and not taking a dodgy path to try and skirt medical devices regulations.


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    Chris Barkway
    Petersfield
    United Kingdom
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    Original Message


  • 9.  RE: Wearable vibration therapy: Class I (rule 13) or Class IIa (rule 9)

    This message was posted by a user wishing to remain anonymous
    Posted 21-Feb-2022 12:42
    This message was posted by a user wishing to remain anonymous

    There are some thoughtful arguments provided here for different approaches to conformity assessments (classification) for the device.  I am not sure that I could be convinced that some component of your device is not active based on the definition unless there is a generic battery source/plug already on the market that's used to generate the energy; however, I tend to read the definition a little differently.  I tend to read that second part of the definition as applying to systems where there is an active device providing the power and other functionality (output) to which another device can be connected to get the output to the patient without changing it.  I could see, using a TENS unit as an example, that the TENS unit itself generates/controls the intensity/frequency/pattern of the impulses delivered and would be considered an active device.  The wires and pads that attach that are designed only to deliver those impulses at the intensity/frequency/pattern generated could fall under the non-active device definition.  Now, depending on where your power source connects to (or is integrated) into the design, where the vibrations are generated and whether or not the wearable component has functionality that focuses/concentrates/adjusts frequency of the power unit's output ... maybe you could argue that the wearable part is not active?  Regardless, the device will have an active component and it would be up to you to support everything active happens at your power source and classify it accordingly and argue that the connectable, wearable part is a Class I device that simply delivers the output without significant change.  I guess the main question is where the electrical energy from the battery is converted to vibration ... and start there.

    At this point, I would be trying to figure out what the risks are for the business based on the conformity assessment route and resulting classification.  Depending on your notified body and your relationship with them, you can ask them to review your proposed conformity assessment route, but you need to be very clear in the description of your device and how it operates.  It will not help you in the long run to get an interpretation based on incomplete or inaccurate information.  Whatever they are willing to accept is what they are willing to defend to the EU Commission as they are under much higher scrutiny under MDR for conformity routes.  In this day and time, I would be cautious of putting your relationship with your notified body at risk by not being fully transparent.  If you were to try to go straight Class I on this/these device(s), the other risk is the level of effort required to build the necessary technical documentation for a Class I vs a higher classification of device.  What's the impact to your time-to-market approval if, at any point, your Class I assessment is not accepted?  There's really nothing more professionally frightening to me than to think about putting work into holding on to a Class I conformity route, finding out down the road that my argument was not accurate, and then trying to pull the additional information/data required for a reclassification, particularly if/when additional testing and technical documentation is required that could have been completed already if the conformity route assessment had been correct initially.

    You are the one who knows your device best.  These activities are where I feel like I earn my keep.  I will usually present the team with a worst to best scenario, discuss the regulatory/business/timeline risks associated with each scenario and ensure any decisions to move forward "at risk" are clearly documented.
    Original Message


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