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Know What Time It Is? Your Medical Device Doesn't
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."
Why can't the medical devices be hardcoded to use an NTP server on the hospital's LAN?
NTP does not require access to public networks. Private time servers, usually GPS sourced via rooftop antennas, are very common.
Can You Say Linux? I Knew That You Could.
You don't need to connect to an outside server. You can easily run your own time source (GPS is really easy these days), or have the devices talk to a single internal server which then securely contacts outward. If they're off, at least they're all on the same time. It's really dangerous if everything is reporting different incorrect times.
Look if the options are 24 minutes of random error or say 24 seconds of consistently biased error in all the devices in the hospital, I'll take the consistent bias any day. The point of all of this is so that a nurse walking into the room and seeing a blue lipped coma patient can determine things like how long has it been since the monitor whose leads fell off last recorded an accurate O2 saturation.
((lambda (x) (x x)) (lambda (x) (x x))) http://www.endpointcomputing.com a scientific approach to custom computing.
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.