An epidermal patch for the simultaneous monitoring of haemodynamic and metabolic biomarkers, 2021, Sempionatto et al

Prototype.

"Monitoring the effects of daily activities on the physiological responses of the body calls for wearable devices that can simultaneously track metabolic and haemodynamic parameters. Here we describe a non-invasive skin-worn device for the simultaneous monitoring of blood pressure and heart rate via ultrasonic transducers and of multiple biomarkers via electrochemical sensors. We optimized the integrated device so that it provides mechanical resiliency and flexibility while conforming to curved skin surfaces, and to ensure reliable sensing of glucose in interstitial fluid and of lactate, caffeine and alcohol in sweat, without crosstalk between the individual sensors. In human volunteers, the device captured physiological effects of food intake and exercise, in particular the production of glucose after food digestion, the consumption of glucose via glycolysis, and increases in blood pressure and heart rate compensating for oxygen depletion and lactate generation. Continuous and simultaneous acoustic and electrochemical sensing via integrated wearable devices should enrich the understanding of the body’s response to daily activities, and could facilitate the early prediction of abnormal physiological changes."

Open access.

Sempionatto, J.R., Lin, M., Yin, L. et al. An epidermal patch for the simultaneous monitoring of haemodynamic and metabolic biomarkers. Nat Biomed Eng (2021).

https://doi.org/10.1038/s41551-021-00685-1

 

Shorter press release about the study (which is TL;DR).

"New Skin Patch Brings Us Closer to Wearable, All-In-One Health Monitor

Engineers at the University of California San Diego have developed a soft, stretchy skin patch that can be worn on the neck to continuously track blood pressure and heart rate while measuring the wearer’s levels of glucose as well as lactate, alcohol or caffeine. It is the first wearable device that monitors cardiovascular signals and multiple biochemical levels in the human body at the same time."

More at https://ucsdnews.ucsd.edu/pressrele...-closer-to-wearable-all-in-one-health-monitor

It's work in progress (prototype stage) but could come in useful for ME research if they can make it work accurately enough. One ME-specific problem I see though is that the sweat sensors like for example lactate - continuous monitoring of which would be very interesting - seem more accurate after exercise when people actually sweat. I can't recall the last time I worked up even a slight sweat (not counting the tediously frequent night sweats).

 

What I don't get is....prior to extensive monitoring of large numbers of people (populations sized groupings), to determine what is 'normal', how can they tell if people wearing them are having "abnormal physiological changes".

As far as I know all of the reference points that are currently used do not allow for anything other than the odd static measurement. In other words 'some guy', probably in a likely military hospital in the 1950s, with half a dozen patients, seems to have decided what 'normal' is for a whole host of test results. On the basis of static results.

Logically this must be so.

 

Chicken and egg I guess. You can't monitor large numbers of people to see what's normal until you have a device to monitor them with. And until you've monitored them you can't tell if your device shows normal or otherwise.

 

Diabetics monitor their blood glucose a lot so the normal levels in blood are well worked out. Healthy people may have surges after meals but it soon drops. Blood pressure and heart rates are well categorised as well.

Using this device would give a lot of information about normal physiology but it would be of great benefit to diabetics and people with brittle blood pressure right from the start.

I'd love one!

 

Favourite PhD here for engineering students.

My eldest daughter did a bit of work during her masters (3years ago ) calibrating chemical sensors for a diabetic wristband wearable which a PhD student was working on.
Biotech is a big sector here.

 

Looks like the patch stimulates local secretion of sweat

"The chemical sensors are two electrodes that are screen printed on the patch from conductive ink. The electrode that senses lactate, caffeine and alcohol is printed on the right side of the patch; it works by releasing a drug called pilocarpine into the skin to induce sweat and detecting the chemical substances in the sweat. The other electrode, which senses glucose, is printed on the left side; it works by passing a mild electrical current through the skin to release interstitial fluid and measuring the glucose in that fluid."