In my work as a veterinary tech (AHT not RVT) I take the temperatures of a lot of dogs and cats. I also give a lot of injections. I have noticed that a significant number of patients are more bothered by a thermometer up the arse than by a small needle into the scruff or leg. This led to the sharp thermometer idea.

I would like a digital thermometer with a luer tipped head to accept a 22 gauge needle. This would be inserted subcutaneously or intramuscularly if that wouldn't be accurate enough.

I know that this sounds stupid since needles are painful and rectal thermometers are just uncomfortable but the indignity of a probe up the bum seems to be worse than a little pain for a fair number of animals.

afterthought - before someone tells me to get an ear thermometer; accuracy is difficult to get with a patient that's jumping about as many do with something in the ear, especially if they need a vet to sort an ear infection.
-- stilgar, Jan 30 2006

Welch Allyn http://www.welchall...detail.asp?ID=34091
The thermometer I'm mentally modifying [stilgar, Jan 30 2006]

A great idea. I too have been surprised at the equanimity of animals getting a shot. This makes sense.

I am certain that there are catheter- based thermometers - I think the Swan- Ganz right heart catheter works this way. If it is on a catheter that means it fit through a needle. So it could be left in the needle.
-- bungston, Jan 30 2006


The Swan-Ganz caths I've worked with (thermodilution) used an epoxy-embedded thermistor about 5 cm from the distal tip. Put a cold saline bolus into the heart and watch the temp curve for recovery time, and you can infer cardiac volumetric output. That was a fairly large temp swing, though; I don't know if it has the resolution you'd want for a vitals-type measurement.

The caths ranged from 6.5 to 8 french (about 2 - 3 mm) and had to be skived down for the thermistor to fit - I believe it was a bit bigger than 1 mm. Quite small, but not down to a 22 gauge yet.

I've seen some fluoride-glass optic fibers being developed for IR transmission - they should be capable of a thermal imaging type measurement. Use the needle shell as the fiber sheath - you could probably even get away with a 28 ga. - and it should be quick, cheap, disposable - no sensor necessary in the needle.
-- lurch, Jan 30 2006


Don't mean to stir the pot with the mention of an RF-tagged device... but I thought of a way to accomplish what you want without any more trauma than an animal is already exposed to (and of course, this would be good for people-animals too!).

You know those RFID tags that animals have inserted as a routine procedure? Why not modify one of those to include a thermometer? When the tag is interrogated, it'll return ID, temperature, and maybe more. Of course it'd have to be inserted a little deeper than usual, and therefore may need to be miniaturized a little, but that's up to the engineers. As to the method the tag uses to measure temperature, I can think of a few.

What RFID idea is complete without an LED idea to compliment it? Since one could measure the animal's temperature as often as needed, why not construct a collar with a nice little LED that lights up when Fido's temp gets a little high? For a more accurate measurement - a constant LCD readout.
-- TIB, Jan 30 2006


Wow, I was expecting to get called cruel for inventing a new reason to stick a needle into things. I should elaborate on my intended probe design; I want a luer tip with a very small (approximately 30 gauge I'd guess) wire protruding. This would thread inside the base of a standard disposable needle making the needle itself the probe. This would avoid the need to sterilise the tip each time or buy expensive disposable tips. I'm not sure how well the needles conduct heat, or if they do so consistently enough to allow an accurate result with many different needles though.

As for the rfid idea, gimme. Non-invasive (at least after the initial needle) temperature monitoring would be incredible. No more near heart attacks during surgery when the temp probe falls out of a small patient and the readout plummets (and I know that even a dead animal's temperature doesn't drop like that but I still jump every time). Also, it would help to convince those who are on the fence regarding chips to install them.
-- stilgar, Jan 31 2006


Oh, I'd also like an intravenous pulse-ox probe. No more buggering about trying different clamps and probes, just stick one straight into the bloodstream for a perfect result. This would be a bastard to build though.

oh yeah, and [21 Quest], this could be used in humans but it seems unlikely that anyone would want it to be. We tend to listen when told to sit still and not bite the thermometer so unpleasant rectal readings are rarely needed.
-- stilgar, Jan 31 2006


Don't mix up the rectal and 'sharp' thermometers. (+)
-- hippo, Jan 31 2006



random, halfbakery