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] EN50131-1 Battery spec vs. Environmental class

Amund, You may consider heaters for the low temp ambients and if necessary coolers for the high. You might also consider operationally limiting your charge cycles to only times when the ambient is within acceptable limits and make this a part of your certification by placing it in the conditions

Re: [PSES] EN50131-1 Battery spec vs. Environmental class

If power is available to charge the battery then the product could also employ a battery strip heater thermostatically controlled to bring the temp up to minimum. I have a low voltage low power strip heater on the battery in my listed outdoor gate opener controller. It happens to be a sealed

Re: [PSES] EN50131-1 Battery spec vs. Environmental class

Depends on Security Grade requirements and where the battery is stored. Li batteries can be used in discharge mode to -20C. Have only done one project for this, where the battery temperature was monitored by the charger, and shut down charge current when outside rated temperature range, but

Re: [PSES] UL's Direct Support Requirements symbol on PCB

1. See UL796, 9.1 for support of current-carrying components at specified voltage levels. 2. See UL796, clause 9. Some test methods for DSR rating are in the UL746 series. 3. Yes for PLC, which can 'infer' CTI. Brian From: Vincent Lee [mailto:08e6c8d35910-dmarc-requ...@ieee.org] Sent:

Re: [PSES] distribution xfmrs

Brian, I have reviewed the federal regs for distribution transformers including the 2016 final rule which I expect to provide detailed commentary on what is in and out of scope, and why, and I find only one occurrence of 'door', and it is not an exclusion/exemption. Hopefully your customer

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