Stress monitoring has always been a tricky business. As it turns out, there is a somewhat reliable way of monitoring stress by measuring how much cortisol, the so-called “stress hormone,” the human body produces. With that in mind, bioengineering researchers at the University of Texas at Dallas decided to make CortiWatch, a wearable device for continuously monitoring cortisol excreted in sweat, as a sort of DIY stress meter.
They made their own potentiostat, a device for measure small amounts of current produced by electrochemical reactions, similar to the glucometer. We’ve talked about these types of measurements before. Simply put, the potentiostat contains a voltage reference generator which biases the sensing electrodes at a preset potential. The voltage bias causes local electrochemical reactions at the sensing electrodes (WE in the image above), stimulating electron flow which is then measured by a transimpedance amplifier or “current-to-voltage” converter. The signal is then analyzed by an onboard analog-to-digital converter. Simply put, the more cortisol in the system, the higher the transimpedance amplifier voltage.
To validate their system a bit more thoroughly than simple benchtop studies, the researchers did some “real-life” testing. A volunteer wore the CortiWatch for 9 hours. The researchers found a consistent decrease in cortisol levels throughout the day and were able to verify these measurements with another independent test. Seems reasonable, however, it’s not quite clear to us what cortisol levels they were expecting to measure during the testing period. We do admit that it takes quite a bit of calibration to get these systems working in real-life settings, so maybe this is a start. We’ll see where they go from here.
Maybe the CortiWatch can finally give us a proper lie detector. We’ll let you be the judge.
I want one like the Sheriff (Jackie Gleason) wore in Smokey and the Bandit.
“The researchers found a consistent decrease in cortisol levels throughout the day and were able to verify these measurements with another independent test.”
So, was the test subject aware of the cortisol readings and took steps to reduce (his) stress, or was the test subject given a drug that is known to reduce cortisol levels?
Or do people normally start the day with high levels of stress that reduce as the day goes on?
I think the body produces a certain amount as a get up and go chemical early in the day.
In other words, caffeine.
B^)
Caffeine does stimulate cortisol release, but there is a natural dump on waking, so it’s said that you should have your first coffee a couple of hours after waking up, so you don’t waste the natural surge, or make yourself cortisol insensitive or something. Or it just wastes the coffee because it’s peaking and you’re not really gonna get a boost until later when levels flag.
So they bind antibodies specific to cortisol to an electrode, which alters the electrical potential on the electrode when the antibody binds with a cortisol molecule.
So, you could make an array of electrodes, with antibodies specific for just about anything. SARS-CoV-2, for example…
Well they’ve made a unicorn out of chimp cold germs by sticking the covid spike on them and making antibodies to that, so-o-o-o-o-o-o-o-o maybe?
What to do with no sweat glands? Sebaceous glands method I’m thinking somehow might even be easier?
Isn’t that an extremely rare abnormality?
So for e.g. 99.999% of the population this method would work.
A sebaceous gland method being easier and maybe even more cost effective?
Not sure the exact metric more seriously and I do like the design method of the article system.
In regards to metrics… not thinking “extremely rare abnormality.” May be in some demographics and not so in others. Ranging from having 20 in 100,000 on down. Furthermore, methods to reverse the characteristics and even genetically cure the genetic condition are known… though getting to market has been a challenge. Maybe some day in the future no sweat glands or non functioning sweat glands will be a “extremely rare abnormality” everywhere.
Oh, well… better scrap the idea as ‘hateful’ and ‘exclusive’ if the current social climate is anything to go by.
UTD and Hackaday canceled for creation and coverage respectively.
OMG, for my condition (XL-HED) there are therapeutic and genetic cures for sure for the next generations. Now bringing those to market is another challenge.
Nothing is unlawful in intent, so why can ‘hateful’ and ‘exclusive’ be considered since our U.S. Jurisdiction Constitutional Rights allow for Freedom of the Press and Freedom of Speech. Definitely all peaceful.
This is a neat method that can be used for other testing and studies also. I was just saying to inspire other methods like more 21st Century Cures like. Jeeze
You poor victim. Do you have a GoFundMe to recover from your persecution?
Why did they mirror the picture containing the penny?
The mirrored penny is a “lost cause” revisionist thing. They sneak it in where they don’t think they can get away with Lee’s battle flag. Basically the idea is it’s an opposite version of president Lincoln.
Fascinating. Do you have a source? Or a phrase I can Google for it?
Alternatively, it could be that they originally photographed their device on the left side of the penny, later realized that they wanted the expanded diagram on the right side, and then flipped the photo in post.
What are the odds of that being the case, though?
B^)
Probably about the same as one of the crew of Back to the Future picking 88 Mph randomly…
50:50 ;-)
I wondered about this before the “revisionist” reason was offered and I thought they would not have thought as hard about the final photo comparison side-by-side (not even used the same background or all round lighting on the scale image). Then afterwards it would be quite normal to rearrange so that the left is the first photo they want you to look at but that the zoomed view is next to the device, so the photo needs to be mirrored.
I always understood stress to be the external pressure applied and the response in the subject (the human in this case) was called strain. Why isn’t this a strain sensor? If different people react to the same stress/stimulus/situation with different levels of sweat/cortisol/etc then surely it’s a strain sensor.
Historically, strain sensors measure physical (not chemical) stress, to call it a strain sensor would be confusing.
You might be thinking of materials strain, which I would agree with. But the medical world uses heat stress to mean the thermal / humidity conditions and heat strain as the term for the human response to that thermal stress. Heat strain parameters of interest to studies I’ve read include (beyond various bodily temperatures) metabolic rate, electrolytes, hydration and even quality of sleep. So I’d contend that there’s already a non-“physical” analogue in the medical world that works well and could be usefully employed in wider study of human response to stress.
Did quite a bit of research on this matter a couple of years ago. just measuring skin resistance gets you a long way. there are dips in resistance when you get a stress reaction. also you should use alternating current measurements to avoid galvanic reactions on the skin.
There is a medical disease called Addison’s (look it up) which is caused by lack of cortisol which is produced by the adrenal glands. It is fatal unless treated with… hydrocortisone, another name for cortisol. I know all about this because I’ve had it for 25 years. If this gadget works, it could revolutionise treatment.
The normal body cortisol profile is high around 08:00 in the morning (get up and go!), decreases during the day but with a small peak around 17:00. Then it decreases until about 03:00 at which point it rises to the 08:00 peak.
thank you.
Hi
Where can i purchase the Coriwatch please?
Regards
Tony