The Cove Business Standards Discussion Forums More Free Files Forum Discussion Thread Post Attachments Listing Cove Discussion Forums Main Page
UL - Underwriters Laboratories - Health Sciences
Go Back   The Elsmar Cove Business Systems and Standards Discussion Forums > Medical Devices, Medical Information Technology, Medical Software and Health Informatics > Medical Device Related Standards > IEC 62304 - Medical Device Software Life Cycle Processes
Forum Username

Elsmar Cove Forum Visitor Notice(s)

Wooden Line

Level of V&V in Class II Medical Device (Dialysis Machine)


Elsmar XML RSS Feed
Elsmar Cove Forum RSS Feed

Monitor the Elsmar Forum
Sponsor Links




Courtesy Quick Links


Links Elsmar Cove visitors will find useful in the quest for knowledge and support:

Jennifer Kirley's
Conway Business Services


Howard's
International Quality Services


Marcelo Antunes'
SQR Consulting, and
Medical Devices Expert Forum


Bob Doering
Bob Doering's Blogs and,
Correct SPC - Precision Machining


Ajit Basrur
Claritas Consulting, LLC



International Standards Bodies - World Wide Standards Bodies

ASQ - American Society for Quality

International Standards Organization - ISO Standards and Information

NIST's Engineering Statistics Handbook

IRCA - International Register of Certified Auditors

SAE - Society of Automotive Engineers

Quality Digest

IEST - Institute of Environmental Sciences and Technology


Some Related Topic Tags (Not all threads are Tagged)
class ii medical device, validation (general), verification (general)
Reply
 
Thread Tools Search this Thread Rate Thread Content Display Modes
  Post Number #1  
Old 7th June 2017, 11:19 AM
WeightOnWheels

 
 
Total Posts: 5
Question Level of V&V in Class II Medical Device (Dialysis Machine)

Good day all!
I've been doing V&V in the FAA domain for some time now and just recently came into the FDA domain. For the FAA I'm used to doing formalized Code Reads and formalized Unit Test all the way down to analyzing opcode level code coverage for Do178C Level A components.

I've been notified by my customer that this dialysis machine is class II which surprises me. I would think that it would be class III. Do you have any information or experience on what level of V&V detail will be necessary for the FDA on this type of device? My first reaction would be to do everything down to formalized Code Reads, but of course time is money and I don't want to really do more that what's completely needed (Even though I would if I had the time, I'm all about safety).

I also have a really short time frame to complete this project.

Any information would help and it would be greatly appreciated.

Thank you,

Sponsored Links
  Post Number #2  
Old 7th June 2017, 01:24 PM
Nancylove

 
 
Total Posts: 6
Re: Level of V&V in Class II Medical Device (Dialysis Machine)

The amount of V&V would depend chiefly on the product requirements for the product, the risks identified in the risk analysis, the degree to which prior testing can be used (due to similarity of a prior design), and the product complexity.

I've done quite a bit of V&V; let me know if you need some guidance.
Thanks to Nancylove for your informative Post and/or Attachment!
Sponsored Links

  Post Number #3  
Old 7th June 2017, 01:46 PM
yodon

 
 
Total Posts: 931
Re: Level of V&V in Class II Medical Device (Dialysis Machine)

The foundation for software in medical devices is still being built, I'd say. FDA has some guidance on what they expect in a 510(k) submittal but not much detail. The AAMI / ANSI IEC standard on software life cycle (62304) is a recognized consensus standard (both the :2006 version and the 2015 amendment) and provides more guidance and allows partitioning by safety class.

As Nancylove points out, your V&V should be driven by risk. And you should identify what your plans are for V&V in a V&V Plan. The Plan should establish the basis and rationale for exercises such as code reviews (per 62304 this would be probably considered unit acceptance).

A couple of more things that are coming to the forefront in FDA consideration: cybersecurity and usability. For the former, they are wanting to see assurance that reasonable means have been taken to protect from cybersecurity threats. For the latter, they want to see that a risk-based approach to usability has been taken, including validation that the system can be used safely and effectively.
Thanks to yodon for your informative Post and/or Attachment!
  Post Number #4  
Old 7th June 2017, 02:12 PM
WeightOnWheels

 
 
Total Posts: 5
Re: Level of V&V in Class II Medical Device (Dialysis Machine)

Thanks all!

You mentioned that code review could be considered for unit acceptance.
Do you mean instead of doing actual unit tests?

It's a bit difficult for me since I'm used to doing requirement based unit tests including code coverage analysis.

Do you think dialysis machines should fall under class C software for class B software?

"I've done quite a bit of V&V; let me know if you need some guidance."
Thanks Nancylove, I might have to take you up on that guidance.

Last edited by WeightOnWheels; 7th June 2017 at 02:54 PM. Reason: Added comment
  Post Number #5  
Old 8th June 2017, 08:51 AM
yodon

 
 
Total Posts: 931
Re: Level of V&V in Class II Medical Device (Dialysis Machine)

Quote:
In Reply to Parent Post by WeightOnWheels View Post

You mentioned that code review could be considered for unit acceptance. Do you mean instead of doing actual unit tests?
Correct but let me clarify just a bit (I kind of jumped ahead). You have to define what you will do for unit verification and then establish the acceptance criteria for whatever you do. If unit testing is your unit verification approach then there are some specific things to do and to capture.

Quote:
In Reply to Parent Post by WeightOnWheels View Post

It's a bit difficult for me since I'm used to doing requirement based unit tests including code coverage analysis.
That's certainly a valid approach. The standard implies that a certain level of rigor is needed for Class B but additional rigor is needed for Class C. Since you have a little more flexibility, let the risk drive the rigor.

Quote:
In Reply to Parent Post by WeightOnWheels View Post

Do you think dialysis machines should fall under class C software for class B software?
Realize first that if the architecture supports it, you can have different safety classes for software items in the system.

That said, it's hard to say without knowing exactly what the risks associated with the software are. If failure can lead to death or serious injury (and there are no hardware controls implemented - or as the update puts it controls external to the software system) then yes, C is appropriate.
Thanks to yodon for your informative Post and/or Attachment!
  Post Number #6  
Old 13th July 2017, 07:12 PM
Peter Selvey

 
 
Total Posts: 859
Re: Level of V&V in Class II Medical Device (Dialysis Machine)

About 10 years I did a lot of work with dialysis machines in Japan. Generally the construction is a 3 CPU system with one CPU for display and network, one for control and one dedicated to safety. The safety CPU has it's own set of sensors and is generally independent of the control CPU.

Although it is still extremely high risk (there are about 10 different ways to directly kill the patient), the separation of control and protection CPU makes things best suited for Class B approach, with extra emphasis on whole system tests.

It's likely that many manufacturers will be pushed to declare Class C for the safety CPU, but in practice it would be difficult to follow as there is a huge amount of software to pull apart. So it would likely be a fudge job if declared as Class C. There is definitely value in running through the code and checking variables for range limits, overflow, reset, but as for spending a huge amount of time writing up algorithms, well, us humans are pretty bad at trying to visualise or predict what happens in dynamic systems.

We found it was much better to run the tests on the whole system (hardware and software). There were often unexpected results that no amount of code inspection would have revealed. So, if you have limited time, I'd recommend to lean towards more system testing.
  Post Number #7  
Old 17th July 2017, 10:11 AM
WeightOnWheels

 
 
Total Posts: 5
Re: Level of V&V in Class II Medical Device (Dialysis Machine)

Thanks for the reply Peter. Since you were specific on the ways dialysis machines can kill people, Can you tell me what those 10 ways are? (This may may give me guidance on which components need most scrutiny)
  Post Number #8  
Old 17th July 2017, 08:04 PM
Peter Selvey

 
 
Total Posts: 859
Re: Level of V&V in Class II Medical Device (Dialysis Machine)

Of the top of my head:
- overheating
- air infusion
- high flow rate
- wrong dialysate composition
- removal of too much / too little waste fluid
- blood loss (detached return needle, burst tube or other disconnection, leaking dialyzer)
- gross heparin delivery
- failure to disinfect
- failure to remove disinfectants after cleaning

These are basically covered by IEC 60601-2-16. There may be special functions or features in the equipment like feedback loops based on blood volume sensors. Not all are 100% sure to kill but most are fairly dangerous.

The standard requires not only independent protection but also start up tests of the protection and in some cases high frequency periodic monitoring of critical systems like air infusion, which can detect a fault in the protection before the air bubble can reach the patient.

So safety is primarily achieved by redundancy and self testing rather than relying on perfect code. This is normally the case in any high risk system.

In principle, if you have two completely independent systems that are 99.9% reliable (e.g. Class B controls) that gives you overall 99.9999% reliability. In practice it's not quite that simple but that's the basic concept.
Reply

Lower Navigation Bar
Go Back   The Elsmar Cove Business Systems and Standards Discussion Forums > Medical Devices, Medical Information Technology, Medical Software and Health Informatics > Medical Device Related Standards > IEC 62304 - Medical Device Software Life Cycle Processes

Bookmarks



Visitors Currently Viewing this Thread: 1 (0 Registered Visitors (Members) and 1 Unregistered Guest Visitors)
 
Thread Tools Search this Thread
Search this Thread:

Advanced Forum Search
Display Modes Rate Thread Content
Rate Thread Content:

Forum Posting Settings
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Emoticons are On
[IMG] code is On
HTML code is Off


Similar Discussion Threads
Discussion Thread Title Thread Starter Forum Replies Last Post or Poll Vote
IEC/EN 60601-2-39 Peritoneal Dialysis Machine Standards E-N-E-N IEC 60601 - Medical Electrical Equipment Safety Standards Series 3 18th March 2014 06:22 AM
Level of Concern for Class II Medical Device Software 510(k) Submission tebusse 21 CFR Part 820 - US FDA Quality System Regulations (QSR) 3 24th October 2012 03:59 PM
Dialysis Machine is CE Marked as a Medical Device - Accessory or not? Rob Udo EU Medical Device Regulations 4 15th August 2012 04:33 AM
About Dialysis Medical Device Products Registration LQ. Fanny Lozano Other Medical Device Regulations World-Wide 2 28th September 2011 09:52 AM
Customer Notification Requirements - New Packaging Machine for Class 1 Medical Device Ktrna ISO 13485:2016 - Medical Device Quality Management Systems 1 18th July 2011 10:26 PM



The time now is 12:40 AM. All times are GMT -4.
Your time zone can be changed in your UserCP --> Options.


 
 


NOTE: This forum uses "Cookies"