Core Body Temperature lab

So remember the lab for my HK*4320 course that I talked about earlier on in the semester? It happened today, and I ended up being the subject since I was strapped on to do VO2 Max test for the previous lab, I basically looked like this:

VO2 Max Test

A VO2 Max measures the maximal amount of oxygen a person can utilize, to test that, the subject is to undergo exercise with increase resistance at time intervals until either the subject voluntarily fatigue or the VO2 Max data reaches a nice plateau, the former being the more likely outcome. We also measured heart rate wirelessly (in the picture, the black strap around the subject on the bike), other data measured includes ventilations rate, lung tidal volume, won’t get into too much detail. My result for that one test was 52.8ml/kg/min (25.8ml of oxygen used per kilogram of body weight in one minute), which translates to 2972 ml/min in total! That apparently is pretty fit, so I’m happy with my result.

HT 150002 CorTemp Core Body Temperature Sensor

Anyways, back on track. So today’s lab on body thermo regulation had me biking for a good 30 minutes (suppose to be an hour total) at 62.5% of my VO2 Max. Every ten minutes I would be weighted (weight loss = water loss through sweat and breath!), and while I’m biking, my skin body temperature is recorded, as well as my core body temperature. Don’t worry, we didn’t measure it rectally, instead, I ingested a CorTemp™ Core Body Temperature Sensor that wirelessly transmit my core body temperature from the gut. The sensor was coated with a silicone coating so it wouldn’t digest in my body, the thing has all sorts of batteries and circuit in it (see diagram below). I felt weird when my lab TA could come up to me and get some sort of “signal” from his recorder.

Core Body Temperature Sensor Schematic

Speaking of my TAs, they’re a hoot! When I was asked to volunteer as a subject again, I agreed to it knowing nothing was going to go up my “exit”, the conversation went like this:


TA: “Oh yea Tim? You’re going to volunteer? Even though we talked about it yesterday in your lab (my other course, respiratory phys. lab)?”

Me: “Yup, seeing that I don’t see anything about rectum on the board.” (Class laughs)

TA: “Well that’s because we’ve written it in white markers, you’re screwed, literally!” (Class in stitches)

When one of my other TA was explaining to me how the sensor works: “I know it’s an expensive equipment, but please don’t try to recover it, if you see it, just wave it goodbye!”

And once the sensor worked: “Excellent Tim, we now know how hot you are… I meant that in terms of temperature, let’s not get me fired.”

Anyways, I managed to bike for a good 30 minutes, I was suppose to go longer, but when I went for a weight-in on the other side of the room, the sudden stop of exercise and standing up caused a loss in hydrostatic pressure and I felt really quite dizzy and wanted to throw up, and that was when my Prof stopped the experiment. Oh well, we got good data, would’ve been awesome to go longer. Next year the weight-in will be done right by the bike to prevent this from happening, yay for being a guinea pig!

It’s still kind of funny knowing that there’s a sensor in your gut right now just beepin’ away. Imagine going through some sort of security metal detector today, that would make me quite a suspicious character indeed!