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

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

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

“… 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

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

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

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

“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

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

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

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

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

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

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

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

“… 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

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

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

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

… 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

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

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. 

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

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

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

… 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

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

lt;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

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

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] Med

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

: "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 i

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

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

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