FDA wants electrical safety testing on battery powered medical device

[Jimbo]

Hello all. I'm new to this forum. I check in from time to time. I'm hoping the brain trust can help with this issue. I have a device in with the FDA on a 510(k) submission. The legally marketed predicate device is made by my company for 14 years. It is a battery operated pain management device like a TENS but not a TENS. We have performed over 400 tests for all areas of development. We conform to many standards and guidance documents. The FDA is asking us to conduct tests on electrical safety. This is where I tell you that the proposed device is battery powered. 4 AA primary batteries. No lithium. No chance for incorrect installation (polarity). No battery charging. No mains power. Hardware limitations such as low inductor values in power supply. No temperature concerns even at max output. Tested every each way except no mains testing because we can't (no mains). BF applied parts are part of the system so we have tested for safe current & touch current. All current tests have been below thresholds. EMC tests are all green.

How do I satisfy Electrical Safety testing requirements when there really aren't any for battery operated devices? I don't know how to reply to the FDA except whine and tell them they are wrong; I hate to do that.

 

[yodon]

It may help if you post the exact wording from the finding. It's easy to go down the wrong rabbit-hole based on assumptions.

Also unclear about what testing you DID do. Is all the testing you did on the new product or the predicate? Did you do the testing or did an accredited lab do the testing? Quite a bit has changed in 14 years so what was acceptable then may not be acceptable now.

 

[Jimbo]

It may help if you post the exact wording from the finding. It's easy to go down the wrong rabbit-hole based on assumptions.

Also unclear about what testing you DID do. Is all the testing you did on the new product or the predicate? Did you do the testing or did an accredited lab do the testing? Quite a bit has changed in 14 years so what was acceptable then may not be acceptable now.

Hi Yodon,

Here's the exact quote: "Furthermore, it is unclear whether electrical safety of the subject devices was tested". The context was a comment letter from the reviewer in which several minor deficiencies were noted. Some were clear and fair while others just demonstrated the reviewers lack of knowledge on the subject. I pointed out the two tests that I thought were relevant for battery powered devices and he said there were dozens more that I missed. When I asked in the phone call what he meant about electrical safety he said to look for the "electrical safety" clauses in the standards. I did and I have again and I have asked testing labs if they knew of any. DICE has not been able to help me. Dice pointed me to the standard. I keep coming up with zeroes and the reviewer just repeats his original statement.

Regarding the other testing, biocompatibility, mechanical properties, EMC, HFE/UE, design outputs from our design development process, many relevant clauses from 60601-1, 60601-1-2, 60601-2-10, 60601-1-11, ANSI/AAMI NS4, ES60601-1 all current versions of the standards. Biocomp testing by SGS, EMC testing by Element, mechanical by Consolidated Labs in L.A., electrical performance and environmental stuff (chamber) by our tech staff.

All testing was on the new product.

I understand about the 14 years - no kidding.

My last submission was 2 years ago so I think I'm up to date on things. That was a battery and mains powered device. I'd do the testing if I could. With a closed system we can't power the device with mains.

Thank you for giving my problem consideration.

 

[yodon]

Hmm... Do you have maybe a matrix of all the tests you considered showing what you did test and what you excluded with rationale?

Have you maybe looked at similar devices to see what testing they did? (I'm grasping for straws here.)

I understand the frustration when reviewers do the vague "you missed stuff" thing. Maybe a matrix would help pin things down?

 

[Jimbo]

Hi Yodon, yes we have four matrices in our submission.

1. Software requirements to test runs to test cases (all PASS)
2. Our design development specifications. We created test requirements, test runs and test cases. (all PASS)
3. Identified Hazards to test requirements to to test cases (PASS)
4. Multiple standards and guidance documents (such as IEC and ES 60601-1) to requirements, to test cases (PASS). We did a preliminary Risk assessment or evaluation on all clauses and most did not apply for many reasons and we created requirements and test cases for all that did apply. Those that did not apply we included a rationalization to accompany the DNA determination in the third matrix in the list above. in the matrix.

The matrices are confidential and voluminous. We know what we're doing and this is our sixth 510(k). I have just received an email from NTS, I'm sure you know who they are, and they just told me they can't help with electrical safety testing for a battery powered device because (this is my inference) they can't find anything to test. Why else would a national testing lab decline a medical device company's business.

I think I may need to get a supervisor involved.

Thanks for giving this issue your time.

Jimbo

 

[Jimbo]

Yodon, I forgot to add that our primary predicate is our own device and I know precisely what testing we did associated with the submission for that device. It was a combination mains and battery powered device and our testing was different due to the mains part. Other battery operated devices on the market are made in China and their technical file, if there is one, is closed to us.

The curious thing is that we have made a device that delivers a similar therapy and is safer because we don't have any mains risk.

Jimbo

 

[yodon]

Well, I'm out of ideas. Seems like you should have some way to escalate to get specific things they feel they need.

 

[Aki K]

Hi Jimbo,

Did you or NTS test all the relevant cases from 60601-1 subclause 8.4? For examble the patient auxiliary current? I have seen some cases when this is ignored totally (for internally powered devices) even though the standard clearly says the compliance is checked by mesurement (according to 8.7.4).

br Aki

 

[Enternationalist]

I've had trouble before with FDA just making completely fundamental errors and not understanding things. I still don't really know how to go about correcting them, as there's not a lot of leeway to tell them when they're wrong. It's very frustrating. To a certain extent, I take it as a failure to properly explain the nature of the product - but the level of wilful ignorance and apparently not reading documentation at all makes it pretty tough.

 

[Jimbo]

Likewise. I have had very good luck recently going over the head of the person I'm talking to. There are good people higher up. The FDA is like any other business in that they have turnover and new people have to learn and gain experience. Going over the head is not frowned on by FDA managers because they view it as an opportunity to train and improve.

It's also good to know that the FDA is making a concerted effort to raise their customer service ratings - just like a business. I've seen a marked improvement so I'm supporting them.

Hang in there and work hard at explaining your device so they can come to share your understanding. Fighting the FDA never works. Understanding and persuasion with cogent arguments works well. It's always helpful to have other devices or decisions to point to.

I've been there many times. Good wishes.

Jim