PLOS Science Wednesday: Hi reddit, my name is Mike Snyder, and I recently published a PLOS Biology study showing wearable biosensors track useful physiological information for health, and can even distinguish insulin sensitivity from insulin resistance – Ask Me Anything!



Have you tracked the effects certain workouts have on people? Is it possible some people would get a bigger benefit from cardio exercises instead of anaerobic exercises?


This is a great question. We are designing studies for wearables where they will do the exact same exercise and we can measure individuals effects. We are already doing this for bichemical measurements to see differences (e.g. metaoblomics). We do not know the results yet but I expect everyone will be different and it willbe fun to correlate their microbiome, food etc.

Have you looked into Crohn's disease and IBD?


No this wold be great to look at for sure, given the flare ups (Sorry I missed your question earlier).

Would you say there is anything you particularly hope to see this technology be able to effectively monitor in the foreseeable future?


In the next few years I would like to see us have an iPHONe dashboard that collects information from you smart watch and alerts you to early stages of inflammatory disease (colds, Lyme disease) and Type 2 diabetes. I think it can also be used for neurological diseases (e.g. epilepsy) and autimune diseases and hopefully heart diseases.

Thank you for doing this. Have you also been looking into identifying and mapping larger trends such as outbreaks of the flu by aggregating the data by location? I'm not sure the science or legality behind this, but could you theoretically identify a trend quick enough to say, send a warning out to people in a certain area to get vaccinated if early symptoms begin appearing in large numbers in their region?


I think I covered this, but may have accidently deleted it--regardless, I agree that if the data were shared this could be very powerful for detecting outbreaks, but people need to share their data.

Thank you for doing this. Have you also been looking into identifying and mapping larger trends such as outbreaks of the flu by aggregating the data by location? I'm not sure the science or legality behind this, but could you theoretically identify a trend quick enough to say, send a warning out to people in a certain area to get vaccinated if early symptoms begin appearing in large numbers in their region?


Yes, I think so. People would have to be willing to share their data but if they do that this could be quite useful. --.e. detect a high frequency of elevated heart rates in a given location.

With respect to the detection of inflammatory signs, do you think this could be useful to clinicians in its present state? That is, does it provide greater nuance, sensitivity, specificity, or usefulness in differential diagnosis than running a sed rate would? Or do you feel it needs to be further refined before it can be useful to clinicians?


More development i needed but I do not think we are very far from being able to implement this broadly. I think the sensitivity can be tuned a a personal level. You might not want someone running to the docotr everytime they get teh earliest sign of a mild illness, but you might want them to stay home so they do not infecct lots of other folks. Of course for serious illness, like Lyme disease they need to see a doctor. That signature is unmistakable--it was extremely strong, at least for my case.

Are there concerns about privacy with these devices collecting/measuring sensitive health data?

As these devices become more popular, do you think more regulatory measures are needed to help consumers protect their health/physiological data from companies looking to profit off of it?


Privacy: There cold be issues if you determine you are at risk for a disease and you provider discriminates against you, which should not be possible for an existing condition. I would argue it is better to get these measurements and manage your health better, than stay private, but that is a personal decision. I wold also argue health care providers should be paying you (or offering you a discount) because I think you will manage you health better if you are collecting this information.

I think the devices and algorithms need reasonable testing and establishment of validity and this will require some regulatory oversight. For detecting common is should be similar to that of an oral thermometer. For something more serious this will likely require more regulatory oversight by the FDA.

Hi Dr Snyder, thanks for participating in our AMA today!

Can you provide more information about the accuracy of these devices? What is the validation process like?

Also, if a researcher discovers a device on the market is flawed or inaccurate, what is the next course of action? -SK


For most of the devices that we have used, some measurements are quite accurate, for example heart rate and SpO2, and even steps and activity are pretty good. Even for devices that are less accurate you can still detect difference from baseline, and that is the key point—early detection of differences relative to your healthy baseline.

I suspect that the measurements made from these devices are more accurate than the measurements obtained during a brief visit in the doctors office. From wearable data, you can easily extract baseline (resting) heart rates, skin temp and other measurements by looking at a person dashboard for any length of time you want—days, weeks months, etc We think this will be very powerful.

For device validation many companies do very extensive validation before they hit the market, usually with physician input. We perform our own internal valdiation of each device that we used just to be sure and impartial--it help us select the devices that we used.

If a device is generally flawed, I am not sure what the course of action is beyond blog posts and perhaps publishing the results. For an individual device one can reach out to the manufacturer and get a replacement--we have had not problem with that.

Do you think the excessive use of wearables and focusing on data on oneself has the risk of turning a person into a narcissist?


I hope not. I think the bigger concern would be becoming a hypochondriac, but I hope that i snot an issue either.

Could this be described as the first step in a "Check Engine" light for our bodies?


I hope so. It is crazy that cars have 400 sensors on them and most human have none. We are more important than cars.

I've been mood logging my subjective mood to control and predict moodswings and productivity. Is there any objective physiome variable that is correlated with mood or stress that is easy to discretely track?


I do not know but that would be a great study. I would look at heart rate and oxygen.

What do new wearables (ie not monitoring HR, temp, and oxygen) in the future need to monitor in order to significantly add to chronic diseases that can be identified/monitored? How do you feel about wearables that penetrate the skin, rather than sitting on top like most do today?


It is obvious simplest to stay on top of the skin since noninvasive devices can be worn indefinitely--invasive ones are powerful for things like glucose (maybe ions like sodium, potassium as well as molecules like cortisol so these devices will be less general.

Some types of measurements that would be powerful are not yet continuous (oxygen, blood pressure, ECG) without patches, but new devices are coming that will make this possible. I this will be extremely valuable for chronic diseases.

Hi Mike,

I've followed your work for years. Big fan and read your papers. I have my genome sitting on a hard drive next to me as a set of Illumina files. What are the first things you'd look at? I'm 45, a bit overweight and have high cholesterol, but I'm on a decent exercise program. What wearable devices or tests would you think about first? Thanks and keep up the great work!


Tx for your enthusiasm. Lots of question here. For the genoe interpretation you really need to talk to an expert who can a) evaluate your risk for highly penetrant diseases (e.g. BRCA1, 2, SHBD, etc), b) drug response/sensitivity c) Complex disease risk. This is more controversial, but it did work for me.

For wearables, we like heart rate skin temp, galvanic stress response (i.e. conductance across your skin), sleep and activity. The device we used for the study was Basis Peak because it measured all of these. This device is no longer available.—we are exploring apple watch (we did not exist when we started our study) and fitibit, among others, but presently they do non measure skin temperature and galvanic stress response which we think are important. So I guss you can say we are still looking around

For SpO2, we like the Masimo oximeter because it gives continuous SpO2 measurements. For the future I want ECG, blood pressure and continuous SpO2!

When I was a heavy smoker, airline flights always gave me panic attack. My heart rate used to be around 100bpm. Any study on smoking/ drinking using biosensors?


We are not doing anything with smoking but that would be particularly interesting in the context that you mentioned (e..g airline flights). Many of our folks are recording food and drink so I hope we get correlations with drinking.

Do you see so2 readings being useful during normal day to day life i.e. not flying or going to elevation? Do those readings vary much and how often would they need to be taken?

I have also heard that they are not very accurate during movement/exercise. To get accurate readings would the user need to stay still during each reading?

Thank you for the article it was a fascinating read!


Great question. I am not sure yet because we have not looked at that data as carefully. I suspect those at risk with pulmonary issues would have these effects exposed, perhaps during simples activities such as walking and even more so with biking and running.

I think the heart rates are pretty accurate regardless of the activity--seems to be the case for SpO2 and mild activity--not as sure abotu strong activities.

What can we do about lower O2 levels on planes? I know that bringing your own oxygen bottle on a plane is problematic at best especially without obvious health problems. Do I need to train at high altitudes before a long plane trip? Is there anything I can bring with me that's completely allowed currently on a plane to get more O2 to my brain for that 9 hour flight?


Great question. I think if you have a prescription you could get something from your physician, but I do not know for sure. I would imagine training a high altitudes would be helpful, much like mountain climbers spend a few days at base camp. We did find that folks (at least me) adapt on long flights.

Hello mike,

It is amazing that you would be able to track th progression of type 2 diabetes and also identify inflammatory diseases, do you think that similar techniques would be able to detect the onset of other health problems like Alzheimer's?


Yes for many types of neurological diseases that affect activity and heart rate and other physiology. I do not know enough about Alzheimers to comments on this, but a recent study suggests that those with dementia sleep longer and this is very easy to detect with wearables.

What do you believe will be the nearest-term use by consumers of wearables and healthcare with respect to genomics and proteomics? Any commercial entities your are enthusiastic about, whether or not you are affiliated with them?


Several companies are forming in this area--Arrivale and HLA. I do not know enough to comments about them one way or another. The omics space is carefully regulated so its rollout might be slower.

Physician Assistant here, how could this technology be integrated into clinical use, also any plans to allow the patients electronic medical record and this tech to "talk" to each other?


That would be fantastic. Fro the moment I think the information could be funnelled in as a separate dashboard that the physician could access (we need the right interface), but in the future it could become art of the medical record.

It would be great to have this type of monitoring for normal health conscious people. How possible would it be to make these devices available to the general public?


Some devices are already available and worn by tens of millions of people. Upon completion of our research and further testing, we need validated Apps to go with them.

If this sort of thing is anything you particularly hope to see applied.


As above I want to see it broadly used, especially for caregivers. I defintley want to see a health dashboard become part of you smartphone that becomes and early alert system for disease.

With respect to the general public?


I hope it will become commonplace for all. Most people regardless of income have a smart phone.

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