Re: [PSES] Medical device risk assessment - faulty chargers

[Leo Eisner]

All,

Realize IEC 60601-1, ed. 3.0 or 3.1 requires a process under ISO 14971, per 
sub-clause 4.2.2, so doesn’t matter what you think you need.

Here is the first sentence of 4.2.2 “A RISK MANAGEMENT PROCESS complying with 
ISO 14971 shall be performed"

So, sorry but ISO 14971 MEDICAL DEVICE risk management process is a requirement 
of IEC 60601-1, ed. 3.0, 3.1  and will also be required in 3.2. (I am a member 
of TC 62, SC 62A & D and have been working on Amendment 2 changes to 60601-1, 
3rd edition and been in London for last 2 weeks working on A2).

So, go around in circles if need risk management realize this is a requirement 
of the standard.
 
Thx,
Leonard (Leo) Eisner, P.E.
Principal Consultant, Eisner Safety Consultants
Phone: (503) 244-6151 
Mobile: (503) 709-8328 
Email: l...@eisnersafety.com 
Website: www.EisnerSafety.com 
   
  
  
    

*** Internet E-mail Confidentiality Disclaimer ***
This e-mail message may contain privileged or confidential information. If you 
are not the intended recipient, you may not disclose, use, disseminate, 
distribute, copy or rely upon this message or attachment in any way. If you 
received this e-mail message in error, please return by forwarding the message 
and its attachments to the sender.

Eisner Safety Consultants do not accept liability for any errors, omissions, 
corruption or virus in the contents of this message or any attachments that 
arise as a result of e-mail transmission.
***

> On Apr 17, 2018, at 3:57 PM, Richard Nute  wrote:
> 
>  
> “… does a palliative involve an interchange of energy?
>  
> Yes, chemical energy.  But, no injury.  
>  
> Rich
>  
>  
>  
> -
> 
> This message is from the IEEE Product Safety Engineering Society emc-pstc 
> discussion list. To post a message to the list, send your e-mail to 
> >
> 
> All emc-pstc postings are archived and searchable on the web at: 
> http://www.ieee-pses.org/emc-pstc.html 
> 
> Attachments are not permitted but the IEEE PSES Online Communities site at 
> http://product-compliance.oc.ieee.org/ 
>  can be used for graphics (in 
> well-used formats), large files, etc.
> 
> Website:  http://www.ieee-pses.org/ 
> Instructions:  http://www.ieee-pses.org/list.html (including how to 
> unsubscribe) 
> List rules:  http://www.ieee-pses.org/listrules.html 
> 
> For help, send mail to the list administrators:
> Scott Douglas >
> Mike Cantwell >
> 
> For policy questions, send mail to:
> Jim Bacher >
> David Heald >
> 


-

This message is from the IEEE Product Safety Engineering Society emc-pstc 
discussion list. To post a message to the list, send your e-mail to 


All emc-pstc postings are archived and searchable on the web at:
http://www.ieee-pses.org/emc-pstc.html

Attachments are not permitted but the IEEE PSES Online Communities site at 
http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used 
formats), large files, etc.

Website:  http://www.ieee-pses.org/
Instructions:  http://www.ieee-pses.org/list.html (including how to unsubscribe)
List rules: http://www.ieee-pses.org/listrules.html

For help, send mail to the list administrators:
Scott Douglas 
Mike Cantwell 

For policy questions, send mail to:
Jim Bacher:  
David Heald: 

Re: [PSES] Medical device risk assessment - faulty chargers

[Richard Nute]

 

“… does a palliative involve an interchange of energy?

 

Yes, chemical energy.  But, no injury.  

 

Rich

 

 

 


-

This message is from the IEEE Product Safety Engineering Society emc-pstc 
discussion list. To post a message to the list, send your e-mail to 


All emc-pstc postings are archived and searchable on the web at:
http://www.ieee-pses.org/emc-pstc.html

Attachments are not permitted but the IEEE PSES Online Communities site at 
http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used 
formats), large files, etc.

Website:  http://www.ieee-pses.org/
Instructions:  http://www.ieee-pses.org/list.html (including how to unsubscribe)
List rules: http://www.ieee-pses.org/listrules.html

For help, send mail to the list administrators:
Scott Douglas 
Mike Cantwell 

For policy questions, send mail to:
Jim Bacher:  
David Heald: 

Re: [PSES] Medical device risk assessment - faulty chargers

[Nick Williams]

I knew someone would come back with that reply. 

Technically, it may or may not be correct (does a palliative involve an 
interchange of energy?) but in practice it stretches the original assertion 
beyond any useful application. 

As ever, real life is more complex than it is possible to express in one neat, 
pithy phrase. 

Nick. 




> On 17 Apr 2018, at 21:05, John Woodgate  > wrote:
> 
> If the device transfers energy, but the energy proves ineffective, that is 
> still an 'energy interchange'.  If the device fails to transfer energy, there 
> is no 'cause' to produce an 'effect', so any injury is not due to the device 
> but to some other energy interchange.
> 
> Do we rename the list 'IEEE Philosophical Society'?(;-)
> John Woodgate OOO-Own Opinions Only
> J M Woodgate and Associates www.woodjohn.uk 
> Rayleigh, Essex UK
> On 2018-04-17 20:24, Nick Williams wrote:
>> In the medical device context, no this is not correct because the failure of 
>> the device to provide the claimed medical benefit can be a cause of ‘injury’.
>> 
>> Nick. 
>> 
>> 
>>> On 17 Apr 2018, at 20:17, Richard Nute >> > wrote:
>>> 
>>>  
>> 
>> 
>>>  
>>> Do you agree or disagree with James Gibson’s assertion that
>>>  
>>> “Injuries to a living organism can be produced only by some energy 
>>> interchange”?
>>>  
>>> (ISO 14971, C.2.5 recognizes energy transfer can result in injury.)   
>>>  
>> 
>> -
>> 
>> This message is from the IEEE Product Safety Engineering Society emc-pstc 
>> discussion list. To post a message to the list, send your e-mail to 
>> >
>> 
>> All emc-pstc postings are archived and searchable on the web at: 
>> http://www.ieee-pses.org/emc-pstc.html 
>> 
>> Attachments are not permitted but the IEEE PSES Online Communities site at 
>> http://product-compliance.oc.ieee.org/ 
>>  can be used for graphics (in 
>> well-used formats), large files, etc.
>> 
>> Website: http://www.ieee-pses.org/ 
>> Instructions: http://www.ieee-pses.org/list.html (including how to 
>> unsubscribe) 
>> List rules: http://www.ieee-pses.org/listrules.html 
>> 
>> For help, send mail to the list administrators:
>> Scott Douglas >
>> Mike Cantwell >
>> 
>> For policy questions, send mail to:
>> Jim Bacher >
>> David Heald >
>> 
> 
> -
> 
> This message is from the IEEE Product Safety Engineering Society emc-pstc 
> discussion list. To post a message to the list, send your e-mail to 
> >
> 
> All emc-pstc postings are archived and searchable on the web at: 
> http://www.ieee-pses.org/emc-pstc.html 
> 
> Attachments are not permitted but the IEEE PSES Online Communities site at 
> http://product-compliance.oc.ieee.org/ 
>  can be used for graphics (in 
> well-used formats), large files, etc.
> 
> Website: http://www.ieee-pses.org/ 
> Instructions: http://www.ieee-pses.org/list.html (including how to 
> unsubscribe) 
> List rules: http://www.ieee-pses.org/listrules.html 
> 
> For help, send mail to the list administrators:
> Scott Douglas >
> Mike Cantwell >
> 
> For policy questions, send mail to:
> Jim Bacher >
> David Heald >
> 

Nick Williams
Director
Direct line: +44 1298 873811
Mobile: +44 7702 995135
email: nick.willi...@hucklow.net 

-

Hucklow Net Limited
The Old Methodist Chapel, Great Hucklow, Buxton, SK17 8RG England
Tel. +44 1298 873800, www.hucklow.net 
Registered in England, Company No. 08500758


-

This message is from the IEEE Product Safety Engineering Society emc-pstc 
discussion list. To post a message to the list, send your e-mail to 


All emc-pstc postings are archived and searchable on the web at:
http://www.ieee-pses.org/emc-pstc.html

Attachments are not permitted but the IEEE PSES Online Communities site at 
http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used 
formats), large files, etc.

Website:  

Re: [PSES] Medical device risk assessment - faulty chargers

[Richard Nute]

 

“Injuries to a living organism can be produced only by some energy interchange.”

Not all risk are of energetic nature:

Risk is never a function of energy interchange.  Risk is the “combination of 
the probability of occurrence of harm and the severity of that harm.”

 

Injury is a function of energy interchange.  The objective of product safety 
endeavor is prevention of injury, which is prevention of energy (more than body 
tolerance) interchange.

 

Rich

 


-

This message is from the IEEE Product Safety Engineering Society emc-pstc 
discussion list. To post a message to the list, send your e-mail to 


All emc-pstc postings are archived and searchable on the web at:
http://www.ieee-pses.org/emc-pstc.html

Attachments are not permitted but the IEEE PSES Online Communities site at 
http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used 
formats), large files, etc.

Website:  http://www.ieee-pses.org/
Instructions:  http://www.ieee-pses.org/list.html (including how to unsubscribe)
List rules: http://www.ieee-pses.org/listrules.html

For help, send mail to the list administrators:
Scott Douglas 
Mike Cantwell 

For policy questions, send mail to:
Jim Bacher:  
David Heald: 

Re: [PSES] Medical device risk assessment - faulty chargers

[Gert Gremmen; ce-test]

Life is consist of risk assessments!

If you cross a road, you quickly assess the risk of safely getting to 
the other side.


What you call a scientific method, is a risk assessment based on 
physical hypotheses , but the hypothesis might be wrong tomorrow, or in 
another place. But the chance of getting bitten is that low that you can 
get away with it : Risk assessment.


What we call risk assessment in medical product safety evaluation (and 
now also in LVD and other EC directives to come), is a formal method of 
ranking the risks (visualize FMEA here). Seeing them ordered and (though 
arbitrarily quantizized) allows one to compare to earlier versions of 
the product, helps placing a red line (do not cross that risk level)and 
helps in prioritizing risks.


Risk analysis is not scientific, indeed, it is a method to get hand on 
dangers of all kind of nature.


“Injuries to a living organism can be produced only by some energy 
interchange.”


Not all risk are of energetic nature:

Trivial example:  An interpretation fault risk happened in medical 
staff  paging system where both S and 5 were used to indicate the 
location of  emergencies in numbered corridors in a hospital. At that 
time 8-segment displays were common and renumbering the corridors by not 
using the S was a proposed solution. Risk assessment allowed us to find 
other hazards that might happen if a single segment was defective. 6 
versus b, 7 versus 1. The manufacturer decided that a 7-segment display 
was not the way to go.





Gert Gremmen



On 17-4-2018 1:22, Richard Nute wrote:


… how do you test *objectively* the adequacy of a symbol like the ! in 
a triangle…


The ! is not a safeguard.  Ultimately, the safeguard is some 
prescribed behavior on the part of a person.  The manufacturer of 
equipment can only describe the desired behavior.   The behavior can 
be tested to determine its effectiveness at safeguarding a body.  
However, the manufacturer cannot enforce a behavior.  Hence, a 
behavior safeguard is not necessarily an effective safeguard as is a 
physical safeguard.


… requirement for two layers of plastic film or insulation, in case 
one layer had a pinhole…


The pinhole was a hypothesis.  We totally ignored the fact that the 
insulation system is comprised of solid-air-solid (a thin layer of air 
separated the two layers).  The voltage divides inversely according to 
the capacitance.  Most of the voltage appears across the thin layer of 
air, not the two solid insulations.  So, we built in a failure 
mechanism to thwart a hypothesis.  Fortunately, the system has 
sufficent electric strength and the transient voltages at the electric 
strength voltage are years apart and of short duration that breakdown 
during equipment lifetime is not likely.


Product safety is rife with “conventional wisdom.”

Rich

-


This message is from the IEEE Product Safety Engineering Society 
emc-pstc discussion list. To post a message to the list, send your 
e-mail to >


All emc-pstc postings are archived and searchable on the web at: 
http://www.ieee-pses.org/emc-pstc.html


Attachments are not permitted but the IEEE PSES Online Communities 
site at http://product-compliance.oc.ieee.org/ can be used for 
graphics (in well-used formats), large files, etc.


Website: http://www.ieee-pses.org/
Instructions: http://www.ieee-pses.org/list.html (including how to 
unsubscribe)

List rules: http://www.ieee-pses.org/listrules.html

For help, send mail to the list administrators:
Scott Douglas >
Mike Cantwell >

For policy questions, send mail to:
Jim Bacher >
David Heald >




-

This message is from the IEEE Product Safety Engineering Society emc-pstc discussion 
list. To post a message to the list, send your e-mail to 

All emc-pstc postings are archived and searchable on the web at:
http://www.ieee-pses.org/emc-pstc.html

Attachments are not permitted but the IEEE PSES Online Communities site at 
http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used 
formats), large files, etc.

Website:  http://www.ieee-pses.org/
Instructions:  http://www.ieee-pses.org/list.html (including how to unsubscribe)
List rules: http://www.ieee-pses.org/listrules.html

For help, send mail to the list administrators:
Scott Douglas 
Mike Cantwell 

For policy questions, send mail to:
Jim Bacher:  
David Heald: 

Re: [PSES] Medical device risk assessment - faulty chargers

[John Woodgate]

If the device transfers energy, but the energy proves ineffective, that 
is still an 'energy interchange'.  If the device fails to transfer 
energy, there is no 'cause' to produce an 'effect', so any injury is not 
due to the device but to some other energy interchange.


Do we rename the list 'IEEE Philosophical Society'?(;-)

John Woodgate OOO-Own Opinions Only
J M Woodgate and Associates www.woodjohn.uk
Rayleigh, Essex UK

On 2018-04-17 20:24, Nick Williams wrote:
In the medical device context, no this is not correct because the 
failure of the device to provide the claimed medical benefit can be a 
cause of ‘injury’.


Nick.


On 17 Apr 2018, at 20:17, Richard Nute > wrote:






Do you agree or disagree with James Gibson’s assertion that
“Injuries to a living organism can be produced only by some energy 
interchange”?

(ISO 14971, C.2.5 recognizes energy transfer can result in injury.)


-


This message is from the IEEE Product Safety Engineering Society 
emc-pstc discussion list. To post a message to the list, send your 
e-mail to >


All emc-pstc postings are archived and searchable on the web at: 
http://www.ieee-pses.org/emc-pstc.html


Attachments are not permitted but the IEEE PSES Online Communities 
site at http://product-compliance.oc.ieee.org/ can be used for 
graphics (in well-used formats), large files, etc.


Website: http://www.ieee-pses.org/
Instructions: http://www.ieee-pses.org/list.html (including how to 
unsubscribe)

List rules: http://www.ieee-pses.org/listrules.html

For help, send mail to the list administrators:
Scott Douglas >
Mike Cantwell >

For policy questions, send mail to:
Jim Bacher >
David Heald >




-

This message is from the IEEE Product Safety Engineering Society emc-pstc discussion 
list. To post a message to the list, send your e-mail to 

All emc-pstc postings are archived and searchable on the web at:
http://www.ieee-pses.org/emc-pstc.html

Attachments are not permitted but the IEEE PSES Online Communities site at 
http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used 
formats), large files, etc.

Website:  http://www.ieee-pses.org/
Instructions:  http://www.ieee-pses.org/list.html (including how to unsubscribe)
List rules: http://www.ieee-pses.org/listrules.html

For help, send mail to the list administrators:
Scott Douglas 
Mike Cantwell 

For policy questions, send mail to:
Jim Bacher:  
David Heald: 

Re: [PSES] Medical device risk assessment - faulty chargers

[Nick Williams]

In the medical device context, no this is not correct because the failure of 
the device to provide the claimed medical benefit can be a cause of ‘injury’.

Nick. 


> On 17 Apr 2018, at 20:17, Richard Nute  wrote:
> 
>  


>  
> Do you agree or disagree with James Gibson’s assertion that
>  
> “Injuries to a living organism can be produced only by some energy 
> interchange”?
>  
> (ISO 14971, C.2.5 recognizes energy transfer can result in injury.)   
>  


-

This message is from the IEEE Product Safety Engineering Society emc-pstc 
discussion list. To post a message to the list, send your e-mail to 


All emc-pstc postings are archived and searchable on the web at:
http://www.ieee-pses.org/emc-pstc.html

Attachments are not permitted but the IEEE PSES Online Communities site at 
http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used 
formats), large files, etc.

Website:  http://www.ieee-pses.org/
Instructions:  http://www.ieee-pses.org/list.html (including how to unsubscribe)
List rules: http://www.ieee-pses.org/listrules.html

For help, send mail to the list administrators:
Scott Douglas 
Mike Cantwell 

For policy questions, send mail to:
Jim Bacher:  
David Heald: 

Re: [PSES] Medical device risk assessment - faulty chargers

[Richard Nute]

 

“… well understood risk management process provides a quite scientific and 
systematic method for identification of safety related issues in the 
construction…” 

 

I don’t agree that the risk management process “provides a scientific… method…” 
 

 

ISO 14971 requires identification of the hazards in equipment.  “Hazard” is 
defined as a “potential source of harm.”  “Harm” is defined as “physical 
injury… of people…”  

 

“Risk” is defined as “combination of the probability of occurrence of harm and 
the severity of that harm.”

 

If we apply risk analysis to an ordinary power cord, the severity of the harm 
can be as high as death (due to mains voltage in the power cord).  The 
probability of failure of the power cord insulation can be “tolerable,” which 
would not be acceptable in most risk analyses.  Yet, we accept this risk every 
day.

 

This is one reason why I don’t agree that risk management is an 
all-encompassing safety program.

 

Do you agree or disagree with James Gibson’s assertion that

 

“Injuries to a living organism can be produced only by some energy interchange”?

 

(ISO 14971, C.2.5 recognizes energy transfer can result in injury.)   

 

Rich

 

 

 


-

This message is from the IEEE Product Safety Engineering Society emc-pstc 
discussion list. To post a message to the list, send your e-mail to 


All emc-pstc postings are archived and searchable on the web at:
http://www.ieee-pses.org/emc-pstc.html

Attachments are not permitted but the IEEE PSES Online Communities site at 
http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used 
formats), large files, etc.

Website:  http://www.ieee-pses.org/
Instructions:  http://www.ieee-pses.org/list.html (including how to unsubscribe)
List rules: http://www.ieee-pses.org/listrules.html

For help, send mail to the list administrators:
Scott Douglas 
Mike Cantwell 

For policy questions, send mail to:
Jim Bacher:  
David Heald: 

Re: [PSES] Medical device risk assessment - faulty chargers

[John Woodgate]

Thanks for the explanations. However, I still think that at some point 
risk assessment is inevitable.


John Woodgate OOO-Own Opinions Only
J M Woodgate and Associates www.woodjohn.uk
Rayleigh, Essex UK

On 2018-04-17 00:22, Richard Nute wrote:


… how do you test *objectively* the adequacy of a symbol like the ! in 
a triangle…


The ! is not a safeguard.  Ultimately, the safeguard is some 
prescribed behavior on the part of a person.  The manufacturer of 
equipment can only describe the desired behavior.   The behavior can 
be tested to determine its effectiveness at safeguarding a body.  
However, the manufacturer cannot enforce a behavior.  Hence, a 
behavior safeguard is not necessarily an effective safeguard as is a 
physical safeguard.


… requirement for two layers of plastic film or insulation, in case 
one layer had a pinhole…


The pinhole was a hypothesis.  We totally ignored the fact that the 
insulation system is comprised of solid-air-solid (a thin layer of air 
separated the two layers).  The voltage divides inversely according to 
the capacitance.  Most of the voltage appears across the thin layer of 
air, not the two solid insulations.  So, we built in a failure 
mechanism to thwart a hypothesis.  Fortunately, the system has 
sufficent electric strength and the transient voltages at the electric 
strength voltage are years apart and of short duration that breakdown 
during equipment lifetime is not likely.


Product safety is rife with “conventional wisdom.”

Rich




-

This message is from the IEEE Product Safety Engineering Society emc-pstc discussion 
list. To post a message to the list, send your e-mail to 

All emc-pstc postings are archived and searchable on the web at:
http://www.ieee-pses.org/emc-pstc.html

Attachments are not permitted but the IEEE PSES Online Communities site at 
http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used 
formats), large files, etc.

Website:  http://www.ieee-pses.org/
Instructions:  http://www.ieee-pses.org/list.html (including how to unsubscribe)
List rules: http://www.ieee-pses.org/listrules.html

For help, send mail to the list administrators:
Scott Douglas 
Mike Cantwell 

For policy questions, send mail to:
Jim Bacher:  
David Heald: 

Re: [PSES] Medical device risk assessment - faulty chargers

[Richard Nute]

 

… how do you test objectively the adequacy of a symbol like the ! in a triangle…

 

The ! is not a safeguard.  Ultimately, the safeguard is some prescribed 
behavior on the part of a person.  The manufacturer of equipment can only 
describe the desired behavior.   The behavior can be tested to determine its 
effectiveness at safeguarding a body.  However, the manufacturer cannot enforce 
a behavior.  Hence, a behavior safeguard is not necessarily an effective 
safeguard as is a physical safeguard.

 

… requirement for two layers of plastic film or insulation, in case one layer 
had a pinhole…

 

The pinhole was a hypothesis.  We totally ignored the fact that the insulation 
system is comprised of solid-air-solid (a thin layer of air separated the two 
layers).  The voltage divides inversely according to the capacitance.  Most of 
the voltage appears across the thin layer of air, not the two solid 
insulations.  So, we built in a failure mechanism to thwart a hypothesis.  
Fortunately, the system has sufficent electric strength and the transient 
voltages at the electric strength voltage are years apart and of short duration 
that breakdown during equipment lifetime is not likely.  

 

Product safety is rife with “conventional wisdom.” 

 

Rich

 

 


-

This message is from the IEEE Product Safety Engineering Society emc-pstc 
discussion list. To post a message to the list, send your e-mail to 


All emc-pstc postings are archived and searchable on the web at:
http://www.ieee-pses.org/emc-pstc.html

Attachments are not permitted but the IEEE PSES Online Communities site at 
http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used 
formats), large files, etc.

Website:  http://www.ieee-pses.org/
Instructions:  http://www.ieee-pses.org/list.html (including how to unsubscribe)
List rules: http://www.ieee-pses.org/listrules.html

For help, send mail to the list administrators:
Scott Douglas 
Mike Cantwell 

For policy questions, send mail to:
Jim Bacher:  
David Heald: 

Re: [PSES] Medical device risk assessment - faulty chargers

[John Woodgate]

I don't entirely agree, but the term is certainly vague and subjective.  
The trouble is, it's embedded in step 4 of your procedure.  I think we 
have moved on from it now, but you will surely remember the requirement 
for two layers of plastic film or insulation, in case one layer had a 
pinhole.  It was 'considered' that the probability of two coinciding 
pinholes was acceptably low. If that isn't a risk assessment, I'm not 
writing this message. This is just an example of 'test the adequacy of 
the safeguards'. Many others spring to mind rather readily; how do you 
test *objectively* the adequacy of a symbol like the ! in a triangle, 
meaning, well, I think it has had more than one meaning over the years?


I do wish there was a way of eliminating it, but I don't see one.

John Woodgate OOO-Own Opinions Only
J M Woodgate and Associates www.woodjohn.uk
Rayleigh, Essex UK

On 2018-04-16 21:47, Richard Nute wrote:


I don’t like “risk assessment.”  It is highly subjective and not 
scientific.  Read ISO 14971 or any treatise on risk assessment.


I use the “energy transfer model.”   This is not subjective and highly 
scientific.


It was first proposed by James J. Gibson in 1961:

“Injuries to a living organism can be produced only by some energy 
interchange.”


The first step is to identify the energy sources within a product.  
The second step is to class the energy sources as capable of causing 
injury or not.  The third step is to provide the energy sources 
capable of causing injury with one or more safeguards to prevent the 
transfer of energy to a body part.  The fourth step is to test the 
adequacy of the safeguards.


Easy and straight-forward.  Not subjective.

Rich

-


This message is from the IEEE Product Safety Engineering Society 
emc-pstc discussion list. To post a message to the list, send your 
e-mail to >


All emc-pstc postings are archived and searchable on the web at: 
http://www.ieee-pses.org/emc-pstc.html


Attachments are not permitted but the IEEE PSES Online Communities 
site at http://product-compliance.oc.ieee.org/ can be used for 
graphics (in well-used formats), large files, etc.


Website: http://www.ieee-pses.org/
Instructions: http://www.ieee-pses.org/list.html (including how to 
unsubscribe)

List rules: http://www.ieee-pses.org/listrules.html

For help, send mail to the list administrators:
Scott Douglas >
Mike Cantwell >

For policy questions, send mail to:
Jim Bacher >
David Heald >




-

This message is from the IEEE Product Safety Engineering Society emc-pstc discussion 
list. To post a message to the list, send your e-mail to 

All emc-pstc postings are archived and searchable on the web at:
http://www.ieee-pses.org/emc-pstc.html

Attachments are not permitted but the IEEE PSES Online Communities site at 
http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used 
formats), large files, etc.

Website:  http://www.ieee-pses.org/
Instructions:  http://www.ieee-pses.org/list.html (including how to unsubscribe)
List rules: http://www.ieee-pses.org/listrules.html

For help, send mail to the list administrators:
Scott Douglas 
Mike Cantwell 

For policy questions, send mail to:
Jim Bacher:  
David Heald: 

Re: [PSES] Medical device risk assessment - faulty chargers

[John Allen]

Rich 

 

Steps 1 to 4 are perfectly “sensible” but one needs to formalize the analysis – 
and methods like doing a Failure Modes Effects Criticality Analysis (FMECA) are 
not that “simple” when one has to do it in sufficient detail to prove the point 
(“been there, done that”)!

 

John E Allen

West London, UK

From: Richard Nute [mailto:ri...@ieee.org] 
Sent: 16 April 2018 21:48
To: EMC-PSTC@LISTSERV.IEEE.ORG
Subject: Re: [PSES] Medical device risk assessment - faulty chargers

 

 

I don’t like “risk assessment.”  It is highly subjective and not scientific.  
Read ISO 14971 or any treatise on risk assessment. 

 

I use the “energy transfer model.”   This is not subjective and highly 
scientific.

 

It was first proposed by James J. Gibson in 1961: 

 

“Injuries to a living organism can be produced only by some energy interchange.”

 

The first step is to identify the energy sources within a product.  The second 
step is to class the energy sources as capable of causing injury or not.  The 
third step is to provide the energy sources capable of causing injury with one 
or more safeguards to prevent the transfer of energy to a body part.  The 
fourth step is to test the adequacy of the safeguards.

 

Easy and straight-forward.  Not subjective.  

 

Rich

 

 

 

 

-


This message is from the IEEE Product Safety Engineering Society emc-pstc 
discussion list. To post a message to the list, send your e-mail to 
<emc-p...@ieee.org>

All emc-pstc postings are archived and searchable on the web at: 
http://www.ieee-pses.org/emc-pstc.html

Attachments are not permitted but the IEEE PSES Online Communities site at 
http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used 
formats), large files, etc.

Website: http://www.ieee-pses.org/
Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) 
<http://www.ieee-pses.org/list.html> 
List rules: http://www.ieee-pses.org/listrules.html 

For help, send mail to the list administrators:
Scott Douglas <sdoug...@ieee.org>
Mike Cantwell <mcantw...@ieee.org> 

For policy questions, send mail to:
Jim Bacher <j.bac...@ieee.org>
David Heald <dhe...@gmail.com> 


-

This message is from the IEEE Product Safety Engineering Society emc-pstc 
discussion list. To post a message to the list, send your e-mail to 
<emc-p...@ieee.org>

All emc-pstc postings are archived and searchable on the web at:
http://www.ieee-pses.org/emc-pstc.html

Attachments are not permitted but the IEEE PSES Online Communities site at 
http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used 
formats), large files, etc.

Website:  http://www.ieee-pses.org/
Instructions:  http://www.ieee-pses.org/list.html (including how to unsubscribe)
List rules: http://www.ieee-pses.org/listrules.html

For help, send mail to the list administrators:
Scott Douglas <sdoug...@ieee.org>
Mike Cantwell <mcantw...@ieee.org>

For policy questions, send mail to:
Jim Bacher:  <j.bac...@ieee.org>
David Heald: <dhe...@gmail.com>

Re: [PSES] Medical device risk assessment - faulty chargers

[Richard Nute]

 

… 2 Means of Patient Protection (dielectric and spacings requirements)…

 

I trust this statement is a slip-up. Spacings i.e., clearances, are an indirect 
measure of dielectric strength.  They do not constitute two independent means 
of patient protection.  

 

Note that creepage distances cannot be less than clearances, but (according to 
IEC 60664) are dimensioned based on continuous voltages, not transient voltages 
as are clearances.  

 

Solid insulation is traditionally subject only to a dielectric withstand test 
rather than measuring the distance through the solid insulation.  This is 
because solid insulation has many times the electric strength of air so the 
distance through the insulation can be ignored.  

 

Rich

 

 


-

This message is from the IEEE Product Safety Engineering Society emc-pstc 
discussion list. To post a message to the list, send your e-mail to 


All emc-pstc postings are archived and searchable on the web at:
http://www.ieee-pses.org/emc-pstc.html

Attachments are not permitted but the IEEE PSES Online Communities site at 
http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used 
formats), large files, etc.

Website:  http://www.ieee-pses.org/
Instructions:  http://www.ieee-pses.org/list.html (including how to unsubscribe)
List rules: http://www.ieee-pses.org/listrules.html

For help, send mail to the list administrators:
Scott Douglas 
Mike Cantwell 

For policy questions, send mail to:
Jim Bacher:  
David Heald: 

Re: [PSES] Medical device risk assessment - faulty chargers

[Gert Gremmen; ce-test]

I believe that charging a device within the MDD when connected to a 
patient is not normal use but to be classified (foreseeable) misuse.


Some remarks:

1. An apparatus that requires charging is most often meant to be used 
while not connected to the mains; why use a battery otherwise. Most 
equipment i have encountered using 25 years of product testing included 
a clear disabling mechanism while charging.


2. Often equipment that is not designed to meet the double MOPP/MOOP 
requirements (mostly for cost reasons) uses a battery to meet 
insulation/touch current requirements "the easy way". Connecting the 
device to a charger will immediately make the device unsafe.


3. I have not yet seen a medically approved USB charger, and most 
approved IT chargers do not meet the (constructional) reinforced 
insulation requirements between primary and secondary to be  used in ME 
equipment or leakage/touch  currents.


Gert Gremmen


On 14-4-2018 0:59, Leo Eisner wrote:

Nick,

This is an in process interpretation that is being currently developed 
by IEC TC62 SC 62A WG14 and was supposed to be discussed today in our 
London meeting but the submitter of the request for interpretation was 
not able to make the meeting today.  Part of the draft interpretation 
does mention there are fake chargers out there and they definitely 
will not meet Dielectric, spacings, and leakage current limits.  Also, 
they can reboot computers connected to the network, The submitter of 
the request says: "It has been noted in health care facilities 
recently that certain ME Equipment have rebooted, close down 
prematurely, changed alarm setting, change patient setting due to 
interconnection of other electrical equipment intended to be charged 
or powered.”


USB is not the wisest choice for power as you also have data issues 
potentially depending on the Medical device and it’s connection.  The 
best solution I have seen is 1) turn off or disable patient circuitry 
when connected to USB.

2) disable the software the controls the device.
3) provide additional Reinforced or Double Insulation 2 Means of 
Patient Protection (dielectric and spacings requirements)
4) Do a thorough Risk Analysis per ISO 14971:2007 (that is what IEC 
60601-1:2005 + A1:2012) or in the EU use EN 14971:2012 with the 
associated EN 60601-1, ed. 3.1


Hope this helps,
photo   Leonard (Leo) Eisner, P.E.
Principal Consultant, Eisner Safety Consultants
Phone: (503) 244-6151 <tel:%28503%29%20244-6151>
Mobile: (503) 709-8328 <tel:%28503%29%20709-8328>
Email: l...@eisnersafety.com <mailto:l...@eisnersafety.com>
Website: www.EisnerSafety.com <http://www.eisnersafety.com/>
<http://www.eisnersafety.com/Industry_News/> 
<http://us.linkedin.com/in/leoeisnersafetyconsultants> 
<http://www.twitter.com/EisnerSafety> 
<http://skype:Eisner_Safety_Consultants/> 
<http://plus.google.com/+LeoEisner> 
<http://www.youtube.com/channel/UC6obaID27sjS-bbk0qv0AmQ>


*** Internet E-mail Confidentiality Disclaimer ***
This e-mail message may contain privileged or confidential 
information. If you are not the intended recipient, you may not 
disclose, use, disseminate, distribute, copy or rely upon this message 
or attachment in any way. If you received this e-mail message in 
error, please return by forwarding the message and its attachments to 
the sender.


Eisner Safety Consultants do not accept liability for any errors, 
omissions, corruption or virus in the contents of this message or any 
attachments that arise as a result of e-mail transmission.

***

On Apr 11, 2018, at 8:12 AM, Mike Sherman <msherma...@comcast.net 
<mailto:msherma...@comcast.net>> wrote:


There are a number of documented cases of counterfeit or knock off 
Apple USB chargers that do not pass dielectric testing; a couple have 
been suspected in shock related deaths. This is an unstated 
background to this discussion.


Mike Sherman
Graco Inc.


*From: *"Ari Honkala" <ari.honk...@sesko.fi 
<mailto:ari.honk...@sesko.fi>>
*To: *"EMC-PSTC" <EMC-PSTC@LISTSERV.IEEE.ORG 
<mailto:EMC-PSTC@LISTSERV.IEEE.ORG>>

*Sent: *Wednesday, April 11, 2018 5:20:35 AM
*Subject: *Re: [PSES] Medical device risk assessment - faulty chargers

My first thought: what has the origin of the charger has to do with 
it being potentially faulty? Any device may broke; that's why there 
are requirements for single fault condition.


with best regards,

Ari Honkala

-Original Message-
From: Nick Williams [mailto:nick_willi...@conformance.co.uk]
Sent: tiistai 10. huhtikuuta 2018 19:21
To: EMC-PSTC@LISTSERV.IEEE.ORG <mailto:EMC-PSTC@LISTSERV.IEEE.ORG>
Subject: [PSES] Medical device risk assessment - faulty chargers

Colleagues,

E

Re: [PSES] Medical device risk assessment - faulty chargers

[Leo Eisner]

Nick,

This is an in process interpretation that is being currently developed by IEC 
TC62 SC 62A WG14 and was supposed to be discussed today in our London meeting 
but the submitter of the request for interpretation was not able to make the 
meeting today.  Part of the draft interpretation does mention there are fake 
chargers out there and they definitely will not meet Dielectric, spacings, and 
leakage current limits.  Also, they can reboot computers connected to the 
network, The submitter of the request says: "It has been noted in health care 
facilities recently that certain ME Equipment have rebooted, close down 
prematurely, changed alarm setting, change patient setting due to 
interconnection of other electrical equipment intended to be charged or 
powered.”

USB is not the wisest choice for power as you also have data issues potentially 
depending on the Medical device and it’s connection.  The best solution I have 
seen is 1) turn off or disable patient circuitry when connected to USB.
2) disable the software the controls the device.
3) provide additional Reinforced or Double Insulation 2 Means of Patient 
Protection (dielectric and spacings requirements)
4) Do a thorough Risk Analysis per ISO 14971:2007 (that is what IEC 
60601-1:2005 + A1:2012) or in the EU use EN 14971:2012 with the associated EN 
60601-1, ed. 3.1

Hope this helps,
Leonard (Leo) Eisner, P.E.
Principal Consultant, Eisner Safety Consultants
Phone: (503) 244-6151 <tel:(503) 244-6151>
Mobile: (503) 709-8328 <tel:(503) 709-8328>
Email: l...@eisnersafety.com <mailto:l...@eisnersafety.com>
Website: www.EisnerSafety.com <http://www.eisnersafety.com/>
 <http://www.eisnersafety.com/Industry_News/>  
<http://us.linkedin.com/in/leoeisnersafetyconsultants>  
<http://www.twitter.com/EisnerSafety>  
<http://skype:Eisner_Safety_Consultants/>  <http://plus.google.com/+LeoEisner>  
<http://www.youtube.com/channel/UC6obaID27sjS-bbk0qv0AmQ>
*** Internet E-mail Confidentiality Disclaimer ***
This e-mail message may contain privileged or confidential information. If you 
are not the intended recipient, you may not disclose, use, disseminate, 
distribute, copy or rely upon this message or attachment in any way. If you 
received this e-mail message in error, please return by forwarding the message 
and its attachments to the sender.

Eisner Safety Consultants do not accept liability for any errors, omissions, 
corruption or virus in the contents of this message or any attachments that 
arise as a result of e-mail transmission.
***

> On Apr 11, 2018, at 8:12 AM, Mike Sherman <msherma...@comcast.net> wrote:
> 
> There are a number of documented cases of counterfeit or knock off Apple USB 
> chargers that do not pass dielectric testing; a couple have been suspected in 
> shock related deaths. This is an unstated background to this discussion.
> 
> Mike Sherman
> Graco Inc.
> 
> From: "Ari Honkala" <ari.honk...@sesko.fi>
> To: "EMC-PSTC" <EMC-PSTC@LISTSERV.IEEE.ORG>
> Sent: Wednesday, April 11, 2018 5:20:35 AM
> Subject: Re: [PSES] Medical device risk assessment - faulty chargers
> 
> My first thought: what has the origin of the charger has to do with it being 
> potentially faulty? Any device may broke; that's why there are requirements 
> for single fault condition.
> 
> with best regards,
> 
> Ari Honkala
> 
> -Original Message-
> From: Nick Williams [mailto:nick_willi...@conformance.co.uk] 
> Sent: tiistai 10. huhtikuuta 2018 19:21
> To: EMC-PSTC@LISTSERV.IEEE.ORG
> Subject: [PSES] Medical device risk assessment - faulty chargers
> 
> Colleagues,
> 
> EN 60601-1 3rd ed. requires the manufacturer to take a risk assessment based 
> approach to the safety of their electrical medical products. 
> 
> With the increased used of universal USB power as a source for battery 
> charging, it’s easy for the risk assessment to identify use of the medical 
> device with a potentially faulty charger either because the device 
> manufacturer has not included a USB power adapter/charger wth the product or 
> because the user has chosen to use a charger other than the one supplied by 
> the manufacturer. 
> 
> How far does the manufacturer need to go in order to provide protection 
> against the hazards from a faulty charger, not supplied by them? Bear in mind 
> the hazardous scenarios may include a patient contact device being used while 
> being charged. 
> 
> I await opinions with interest!
> 
> NIck.
> 
> -
> 
> This message is from the IEEE Product Safety Engineering Society emc-pstc 
> discussion list. To post a message to

Re: [PSES] Medical device risk assessment - faulty chargers

[Mike Sherman]

There are a number of documented cases of counterfeit or knock off Apple USB 
chargers that do not pass dielectric testing; a couple have been suspected in 
shock related deaths. This is an unstated background to this discussion. 

Mike Sherman 
Graco Inc. 

- Original Message -

From: "Ari Honkala" <ari.honk...@sesko.fi> 
To: "EMC-PSTC" <EMC-PSTC@LISTSERV.IEEE.ORG> 
Sent: Wednesday, April 11, 2018 5:20:35 AM 
Subject: Re: [PSES] Medical device risk assessment - faulty chargers 

My first thought: what has the origin of the charger has to do with it being 
potentially faulty? Any device may broke; that's why there are requirements for 
single fault condition. 

with best regards, 

Ari Honkala 

-Original Message- 
From: Nick Williams [mailto:nick_willi...@conformance.co.uk] 
Sent: tiistai 10. huhtikuuta 2018 19:21 
To: EMC-PSTC@LISTSERV.IEEE.ORG 
Subject: [PSES] Medical device risk assessment - faulty chargers 

Colleagues, 

EN 60601-1 3rd ed. requires the manufacturer to take a risk assessment based 
approach to the safety of their electrical medical products. 

With the increased used of universal USB power as a source for battery 
charging, it’s easy for the risk assessment to identify use of the medical 
device with a potentially faulty charger either because the device manufacturer 
has not included a USB power adapter/charger wth the product or because the 
user has chosen to use a charger other than the one supplied by the 
manufacturer. 

How far does the manufacturer need to go in order to provide protection against 
the hazards from a faulty charger, not supplied by them? Bear in mind the 
hazardous scenarios may include a patient contact device being used while being 
charged. 

I await opinions with interest! 

NIck. 

- 
 
This message is from the IEEE Product Safety Engineering Society emc-pstc 
discussion list. To post a message to the list, send your e-mail to 
<emc-p...@ieee.org> 

All emc-pstc postings are archived and searchable on the web at: 
http://www.ieee-pses.org/emc-pstc.html 

Attachments are not permitted but the IEEE PSES Online Communities site at 
http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used 
formats), large files, etc. 

Website: http://www.ieee-pses.org/ 
Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) 
List rules: http://www.ieee-pses.org/listrules.html 

For help, send mail to the list administrators: 
Scott Douglas <sdoug...@ieee.org> 
Mike Cantwell <mcantw...@ieee.org> 

For policy questions, send mail to: 
Jim Bacher: <j.bac...@ieee.org> 
David Heald: <dhe...@gmail.com> 

- 
 
This message is from the IEEE Product Safety Engineering Society emc-pstc 
discussion list. To post a message to the list, send your e-mail to 
<emc-p...@ieee.org> 

All emc-pstc postings are archived and searchable on the web at: 
http://www.ieee-pses.org/emc-pstc.html 

Attachments are not permitted but the IEEE PSES Online Communities site at 
http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used 
formats), large files, etc. 

Website: http://www.ieee-pses.org/ 
Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) 
List rules: http://www.ieee-pses.org/listrules.html 

For help, send mail to the list administrators: 
Scott Douglas <sdoug...@ieee.org> 
Mike Cantwell <mcantw...@ieee.org> 

For policy questions, send mail to: 
Jim Bacher: <j.bac...@ieee.org> 
David Heald: <dhe...@gmail.com> 


-

This message is from the IEEE Product Safety Engineering Society emc-pstc 
discussion list. To post a message to the list, send your e-mail to 
<emc-p...@ieee.org>

All emc-pstc postings are archived and searchable on the web at:
http://www.ieee-pses.org/emc-pstc.html

Attachments are not permitted but the IEEE PSES Online Communities site at 
http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used 
formats), large files, etc.

Website:  http://www.ieee-pses.org/
Instructions:  http://www.ieee-pses.org/list.html (including how to unsubscribe)
List rules: http://www.ieee-pses.org/listrules.html

For help, send mail to the list administrators:
Scott Douglas <sdoug...@ieee.org>
Mike Cantwell <mcantw...@ieee.org>

For policy questions, send mail to:
Jim Bacher:  <j.bac...@ieee.org>
David Heald: <dhe...@gmail.com>

Re: [PSES] Medical device risk assessment - faulty chargers

[Ari Honkala]

My first thought: what has the origin of the charger has to do with it being 
potentially faulty? Any device may broke; that's why there are requirements for 
single fault condition.

with best regards,

Ari Honkala

-Original Message-
From: Nick Williams [mailto:nick_willi...@conformance.co.uk] 
Sent: tiistai 10. huhtikuuta 2018 19:21
To: EMC-PSTC@LISTSERV.IEEE.ORG
Subject: [PSES] Medical device risk assessment - faulty chargers

Colleagues,

EN 60601-1 3rd ed. requires the manufacturer to take a risk assessment based 
approach to the safety of their electrical medical products. 

With the increased used of universal USB power as a source for battery 
charging, it’s easy for the risk assessment to identify use of the medical 
device with a potentially faulty charger either because the device manufacturer 
has not included a USB power adapter/charger wth the product or because the 
user has chosen to use a charger other than the one supplied by the 
manufacturer. 

How far does the manufacturer need to go in order to provide protection against 
the hazards from a faulty charger, not supplied by them? Bear in mind the 
hazardous scenarios may include a patient contact device being used while being 
charged. 

I await opinions with interest!

NIck.

-

This message is from the IEEE Product Safety Engineering Society emc-pstc 
discussion list. To post a message to the list, send your e-mail to 
<emc-p...@ieee.org>

All emc-pstc postings are archived and searchable on the web at:
http://www.ieee-pses.org/emc-pstc.html

Attachments are not permitted but the IEEE PSES Online Communities site at 
http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used 
formats), large files, etc.

Website:  http://www.ieee-pses.org/
Instructions:  http://www.ieee-pses.org/list.html (including how to unsubscribe)
List rules: http://www.ieee-pses.org/listrules.html

For help, send mail to the list administrators:
Scott Douglas <sdoug...@ieee.org>
Mike Cantwell <mcantw...@ieee.org>

For policy questions, send mail to:
Jim Bacher:  <j.bac...@ieee.org>
David Heald: <dhe...@gmail.com>

-

This message is from the IEEE Product Safety Engineering Society emc-pstc 
discussion list. To post a message to the list, send your e-mail to 
<emc-p...@ieee.org>

All emc-pstc postings are archived and searchable on the web at:
http://www.ieee-pses.org/emc-pstc.html

Attachments are not permitted but the IEEE PSES Online Communities site at 
http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used 
formats), large files, etc.

Website:  http://www.ieee-pses.org/
Instructions:  http://www.ieee-pses.org/list.html (including how to unsubscribe)
List rules: http://www.ieee-pses.org/listrules.html

For help, send mail to the list administrators:
Scott Douglas <sdoug...@ieee.org>
Mike Cantwell <mcantw...@ieee.org>

For policy questions, send mail to:
Jim Bacher:  <j.bac...@ieee.org>
David Heald: <dhe...@gmail.com>

Re: [PSES] Medical device risk assessment - faulty chargers

[John Woodgate]

There is obviously no unique answer. You can:

- not use USB and provide a charger with a unique connector (my choice);

- use USB, but put full overvoltage and overcurrent protection in your 
product;


- rely on warning notices (not recommended!)

John Woodgate OOO-Own Opinions Only
J M Woodgate and Associates www.woodjohn.uk
Rayleigh, Essex UK

On 2018-04-10 17:21, Nick Williams wrote:

Colleagues,

EN 60601-1 3rd ed. requires the manufacturer to take a risk assessment based 
approach to the safety of their electrical medical products.

With the increased used of universal USB power as a source for battery 
charging, it’s easy for the risk assessment to identify use of the medical 
device with a potentially faulty charger either because the device manufacturer 
has not included a USB power adapter/charger wth the product or because the 
user has chosen to use a charger other than the one supplied by the 
manufacturer.

How far does the manufacturer need to go in order to provide protection against 
the hazards from a faulty charger, not supplied by them? Bear in mind the 
hazardous scenarios may include a patient contact device being used while being 
charged.

I await opinions with interest!

NIck.

-

This message is from the IEEE Product Safety Engineering Society emc-pstc discussion 
list. To post a message to the list, send your e-mail to 

All emc-pstc postings are archived and searchable on the web at:
http://www.ieee-pses.org/emc-pstc.html

Attachments are not permitted but the IEEE PSES Online Communities site at 
http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used 
formats), large files, etc.

Website:  http://www.ieee-pses.org/
Instructions:  http://www.ieee-pses.org/list.html (including how to unsubscribe)
List rules: http://www.ieee-pses.org/listrules.html

For help, send mail to the list administrators:
Scott Douglas 
Mike Cantwell 

For policy questions, send mail to:
Jim Bacher:  
David Heald: 



-

This message is from the IEEE Product Safety Engineering Society emc-pstc discussion 
list. To post a message to the list, send your e-mail to 

All emc-pstc postings are archived and searchable on the web at:
http://www.ieee-pses.org/emc-pstc.html

Attachments are not permitted but the IEEE PSES Online Communities site at 
http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used 
formats), large files, etc.

Website:  http://www.ieee-pses.org/
Instructions:  http://www.ieee-pses.org/list.html (including how to unsubscribe)
List rules: http://www.ieee-pses.org/listrules.html

For help, send mail to the list administrators:
Scott Douglas 
Mike Cantwell 

For policy questions, send mail to:
Jim Bacher:  
David Heald: 

[PSES] Medical device risk assessment - faulty chargers

[Nick Williams]

Colleagues,

EN 60601-1 3rd ed. requires the manufacturer to take a risk assessment based 
approach to the safety of their electrical medical products. 

With the increased used of universal USB power as a source for battery 
charging, it’s easy for the risk assessment to identify use of the medical 
device with a potentially faulty charger either because the device manufacturer 
has not included a USB power adapter/charger wth the product or because the 
user has chosen to use a charger other than the one supplied by the 
manufacturer. 

How far does the manufacturer need to go in order to provide protection against 
the hazards from a faulty charger, not supplied by them? Bear in mind the 
hazardous scenarios may include a patient contact device being used while being 
charged. 

I await opinions with interest!

NIck.

-

This message is from the IEEE Product Safety Engineering Society emc-pstc 
discussion list. To post a message to the list, send your e-mail to 


All emc-pstc postings are archived and searchable on the web at:
http://www.ieee-pses.org/emc-pstc.html

Attachments are not permitted but the IEEE PSES Online Communities site at 
http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used 
formats), large files, etc.

Website:  http://www.ieee-pses.org/
Instructions:  http://www.ieee-pses.org/list.html (including how to unsubscribe)
List rules: http://www.ieee-pses.org/listrules.html

For help, send mail to the list administrators:
Scott Douglas 
Mike Cantwell 

For policy questions, send mail to:
Jim Bacher:  
David Heald: