Know What Time It Is? Your Medical Device Doesn't 290
An anonymous reader writes "A man with one clock knows what time it is, goes the old saw, a man with two is never sure. Imagine the confusion, then, experienced by a doctor with dozens. Julian Goldman is an anaesthetist at Massachusetts General Hospital in Boston. After beginning to administer blood-thinning medication during an urgent neurological procedure in 2005, Mr Goldman noticed that the EMR had recorded him checking the level of clotting 22 minutes earlier. As a result, four hospitals in the northeast had their medical devices checked, and found that on average they were off by 24 minutes. The easy solution that devices could have used since 1985? NTP."
It won't help (Score:4, Informative)
First, they will use Windows Active Directory for NTP because someone will say "it's authoritative for the whole network". And their clocks will be off.
Then they will run into config hell, and blaming that for clocks being off - they will load balance the domain controllers. Which is precisely what you're not supposed to do with NTP. And their clocks will be off.
Then, some small but relevant IT subgroup will secede, claiming that they need "real" NTP. "Network Security" folks are typical suspects here. So their clocks won't match the rest of the gear (which is still off, remember?)
If you have poor enough technology discipline that your clocks are 24 minutes off already, you're probably screwed.
Re:NTP and hospitals (Score:5, Informative)
NTP does not require access to public networks. Private time servers, usually GPS sourced via rooftop antennas, are very common.
Re:Run your own NTP if it matters (Score:5, Informative)
Easy, get a GPS receiver and use its time. The point is that the times all need to be the *same* (so things that happen at the same time are recorded as such); accuracy is secondary. Even if every week or two some guy goes and fixes the clock on the server, that should be acceptable.
Re:Run your own NTP if it matters (Score:5, Informative)
How would that change anything? It just makes all the clocks on the hospital go wrong when it starts to move to wrong times on the NTP server.
You can have one local timeserver that syncs with external trusted servers (nist.gov). All of your local devices can sync with your local ntp server.
Updating it from public sources is out of question too. Think about someone injecting completely wrong time to the hospital.
NTP is *pull*, not push. We've had decades now to bulletproof NTP. It will be pretty easy to nail an NTP server down so it's only going to be serving NTP.
The medical and legal professions are the most IT challenged disciplines I've ever seen, but that may be largely due to excessive gov't regulation.
Re:NTP and hospitals (Score:4, Informative)
Actually a linux server on it's own you can calibrate the system clock to be incredibly accurate. you can calculate the drift of the cmos clock and adjust to get pretty darn accurate.
http://tldp.org/HOWTO/Clock-2.html [tldp.org]
Re:Run your own NTP if it matters (Score:5, Informative)
Re:Run your own NTP if it matters (Score:3, Informative)
You should be a little less paranoid about GPS.
Just because you can find the time and your position using GPS doesn't mean someone can track where you are.
A GPS device is a receiver, not a transmitter.
GPS satellites constantly broadcast the time, and their location. A the GPS in the device takes this data from several (4+) satellites, does the math, and calculates the position.
For this to work the time has to be absolutely correct. So you can use the time to set your clock.
Without some sort of transmitter (like a phone with its data connection, or some sort of dedicated transmitter built into the same device) no one has any possibility of knowing where you are.
Bad administration is a major problem with this (Score:5, Informative)
This is often a case of poor administration, perhaps more frequently than poor design.
For example, I was recently tasked with reviewing the performance of several hospitals in the diagnosis and treatment of stroke. Under national guidelines (UK) a patient with suspected stroke must have had a CT scan within 30 minutes of arrival at hospital, with blood-thinning treatment administered within 60 minutes (if appropriate).
The problem was that the times on the CT scanners were discrepant by +/- 45 minutes from true time - so the images were tagged with the incorrect time. Further, the CT viewing workstations had times up to 2 hours discrepant. The CT scanners were Windows or Gentoo depending on the manufacturer's preference. Similarly, the CT workstations were windows, and were all bound to the hospital domain.
The time discrepancies made my assessment very difficult - and I had to correct for each individual scanner, and assume that the clocks hadn't drifted over the 6 month period of the audit.
I also found several safety issues because of this - e.g. if it was 1am, and a patient had a CT scan, some workstations would be 2 hours slow, so would read 11 pm on the previous day. These workstations would refuse to load the CT scan because the files were filtered by "WHERE [StudyTime] NOW".
I raised a support issue with the workstation vendor who simply said "These are windows workstations. You should ensure that they are appropriately bound to your domain, and configured to sync with your time server or domain controller". So I called IT to configure this, "No way. These are medical devices, we can't change the configuration - and anyway, what will happen if the clock is fast, and the sync pushes the clock back, so that there are 2 occurrences on the same time. That would cause chaos. Even if the manufacturer supports it, there's no way we'll set it up". Of course, their concern doesn't actually exist, because most time sync algorithms (even on Windows) are clever enough to avoid "double time".
There was similar obstruction with the CT scanners. The vendors simply said - we support and encourage synchronisation with a time server. IT or the radiology administrators simply stonewalled the ideas. They refused even to correct the clocks on teh scanners - so the clocks are still wrong to this day (even more so, due to accumulated drift).
Of course, even if the time can be set right - there is disagreement as to how daylight-saving is managed. Some equipment, esp. older embedded kit isn't daylight-saving aware. Do you set it to Summer time or winter time? In most hospitals I've been in, it's been an inconsistent mixture - often with lots of clock drift added, so you can't actually be sure.
Re:Run your own NTP if it matters (Score:5, Informative)
We've had decades now to bulletproof NTP
... and in fact we've already done so. [nist.gov]
There is no excuse for failing to implement it.
Re:Receivers transmit (Score:4, Informative)
There is nothing in the vans.
They just have a list of those who haven't paid the tax and go 'round harrassing people. It's easier and doesn't cost as much as a van full of equipment and high-paid engineers.
Emperor
Clothes
None.
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BMO