EBME Forums Forums Maintenance Technical Assistance Summer / Winter Time

I must admit I'm getting a bit flabby myself - not so much opportunity these days to get out and about. Perhaps the role of "Fat Controller" running a medical device network might suit me though.


Actually, as part of my research and project for my MSc, I had my go at designing & building a box to "retrofit" current visual and audible alarm standards to existing patient monitoring that didn't meet the standards. It's not easy.

The design of an embedded MP3 player and stereo audio system to store the "novel" alarm sounds, a diagnostic display (including decision making, etc) and a robust communications system with the patient monitor using microcontrollers is feasible but difficult.

The "sensor-fusion" aspect, signal processing and establishing scales of severity and an alarm hierarchy that's required took a lot of thinking about and that only involved the device system alarms, heart rate and oxygen saturation with 2 adaptive alarm parameters for each. Difficult.

Best to come up with the specification of what's required and let some whizz-kid programmers and embeddded system designers come up with a finished product.

What we want is for manufacturers to provide a programming interface and memory within the medical device that allows us to adjust time and date, service intervals, store maintenance information and indicate diagnostics or failures.

Sounds like it's time for you to re-consider the Biomed Boot Camp, Mate. Take my advice, Richard, get out of those dirty, unhealthy, hospitals (as I have done), and take the summer one flower at a time! You can still be pondering the best way to implement the Box whilst you’re out walking, jogging, peddling, paddling (or whatever), believe me. Go on and get those wheels of freedom a singing, bells of freedom a ringing!

Hi All,
Looked at the possibility of using bluetooth for equipment location some time ago. The systems are readilly available on the open market and come indifferent guises. However all the systems I looked at were externally fitted and one way comms only.
What you seem to be seeking is the next level. The retro fit would prove extremely difficult with the 'invasion' of an equipment by a foreign body. Causes alsorts of problems with CE marking and 510K registration. Manufacturers would not even consider altering their technical folders to include the re-engineering on equipments that are already some years into their expected life.
If you are then to lobby maufacturers to include a standard comms pack into their equipments, you would be asking them to effectively cut their revenue as any standardise comms pack would only require a standard software package to utilise it and not bespoke packages which we now have to use.

I don’t see the need for invasion at this stage, Rob. So far we foresee a Box that will keep accurate time, and communicate either with a wireless network, with the passing technician, or both. It should display the time somewhere on the exterior of the parent unit (so the Box itself may well be a bolt-on, as it were, rather than inside the unit). It will also log data, to a certain extent initially, and as far as possible eventually. For instance, it would be nice if it made a note of equipment usage, alarm conditions, defib discharges, and stuff like that. That may call for some invasiveness, but I’m wondering if that could be done by eaves dropping on existing signals, rather than “wiring in”. Something to think about, then. It may also include RFID, and possibly mains power signaling (ie, sending signals through the fixed mains-power wiring to another location within the building - easy, then, to notice when the equipment has been unplugged)! It will record data like mains on/off, hours run, and (perhaps) battery condition. It will need to sip its own power from wherever it can steal it (ie, should not rely on the parent unit). It will store basic data like PM dates, and we may decide to include history narrative as well if we find there's lots of memory available. I believe in Open Source technology, free to all to share and make contributions to. It will probably need not only Bluetooth, but 3G, GPRS, GPS, MMS, RS-232, SMS, USB, WAP, Wi-Fi and Off-the-Cuff! Can you have one ready in a week?

OK Richard, you ask the manufacturers. Meanwhile, I’ll get on with something useful. Ha, ha.

Matt’s original post was about GMT, and "changing the clocks" etc. Well, I think we’ve answered that one. Stick to GMT, and if real accuracy is needed, use a device to pick up the Anthorn MSF signal.

Thanks for those words of wisdom Geoff. Good luck with the charity work.

Hey Richard, it looks like you’ll need to be quick about it, Mate!

Interesting - according to a quick calculation the radiated power of the Wi-Fi operating at 2.4GHz is quoted as 18dBm (W) +/-1dBm (W). This appears, to me, worst-case, to approach the limit imposed upon Wi-Fi of 0.1W (0.08W - though I'm assuming isotropic radiation, i.e. ERP, rather than EIRP - don't know the antenna characteristics in the Fluke "Beacon").

0.1W radiated power is about equivalent to that of a mobile phone isn't it? Similar spread-spectrum RF (microwave)transmission scheme to a mobile phone as well (I guess it "chirps" data very briefly). I wonder how they attach to a medical device - directly onto the case with an adhesive pad?

Something a bit more permanent than that, I would have thought.

So, what do you reckon ... should we buy a couple and open them up? With a view to "reverse engineering", of course (surely you haven’t forgotten the hands-on imperative, where the true tech is honour-bound to take a peek inside of every bit of kit encountered?).

I notice that they don't give any clues about pricing, though. Anybody out there have any feedback to offer about the Beacon units?

Meanwhile, I hope that some of you genius guys have come up with some nice suggestions for our own Box over the (wet) Bank Holiday weekend (what else were you doing)?