Monitoring Carotid Blood Flow Using In-Ear Wearable Device During Tilt-Table Testing, 2023, Hemantkumar Tripathi MD et al

[Ken Turnbull]

Reduced Blood Flow to Head in Post-Exertional Malaise
https://lumiahealth.com/blogs/news/reduced-supine-blood-flow-to-head-in-post-exertional-malaise-pem

Finally! I have been suggesting (pestering) for months for them to show a graph from someone with ME/CFS. They call it a flow index.

 

[Mij]

Who's Building the World’s Smallest Wearable Device?Lumia Health™ is! And, we’re finding out that it’s no small task.

What we’re making is not just the “world’s smallest wearable.” It’s also the first wearable device capable of tracking blood flow to your head.

But like so much in life, progress is not always linear. Although we managed to ship the first batches of Beta devices in August, we had to pause shipments due to unexpected Lumia behavior in the field.


You see, simultaneous with our initial release, we updated the Bluetooth architecture to support Direct-to-iPhone data syncing so Lumia Members could see their Flow on the go, without needing to be in the same room as their Light Station.

The unexpected problem that came with that upgrade was that when Lumia was at the edge of being in range with the Light Station, it got a little clingy, trying over and over to connect and demanding more power than our tiny micro-battery could support. The ironic result? Lumia kept fainting.

After a couple intense weeks testing multiple different fixes, we are proud to share . . . Ken fixed it!!! (More about Ken below — he gets his own article.)

And so, after the briefest of manufacturing pauses, we’ve fired up the Lumia forge once more, and we’re making every order anew. As of last week, shipping has resumed!

Isn’t it ironic? The Lumia Origin Story started with fainting, and here we are again!


Also in this edition:

• Fresh brains on deck: Ken Yoshioka has joined Lumia Health™ as CTO.
  
  
• A new research study is beginning for POTS & Long Covid with Dr. Satish Raj.
  
  
• Waiting for your Lumia™ order? I have an estimated shipping timeline update!
  
  
• October is Dysautonomia Awareness Month, and we’re here for it! Lumia Health™ is sponsoring the Boston POTS Walk. Walk, roll, or hang out for a cause.
  
  
• Dr. Amanda Miller and Daniel Ewok Lee have been invited to speak at the American Autonomic Society symposium this November.
  
  
• When will the next wave of Lumia™ orders open?
  
  
• CES 2025 — meet us in Vegas for the Consumer Electronics Show this January.
  
  
• In case you missed it: the replay of our last research webinar with Dr. Miller.

 

[Murph]

I just watched this video and found it quite intriguing.



The following four screenshots show examples of the device measuring drops in blood flow. It measures a proxy for blood flow to the brain but nevertheless looks useful





@SNT Gatchaman you called for this to be done and they have: correlation between in-ear monitoring and Trans-cranial doppler. I'd like to see a bigger sample size and independent testing, but if they were inversely correlated you would not expect to see this correlation even once...










If the device actually does what they hope it will then it produces results similar to a transcranial doppler but can be used in real life (has tiny battery so only measures 10 seconds every 5 mins). Could be a great measure for testing interventions and treatments in POTS maybe even objectively measuring the severity and duraion PEM.

 

[Murph]

It's expensive; not totally out of reach if it actually delivers better ability to manage symptoms. For me i'd need to buy an iPhone to make it work so that's extra expense too! However it's not available in Australia so it's all a bit academic.

 

[Yann04]

Could be a great measure for testing interventions and treatments in POTS maybe even objectively measuring the severity and duraion PEM.

Worth noting that its measures have not been validated as an OI or PEM biomarker or proxy AFAIK.

 

[Eleanor]

has tiny battery so only measures 10 seconds every 5 mins

I was interested until I read that!

The images suggest a much more continuous monitoring, so are there different versions of the device? (I may well have misunderstood)

 

[LJord]

What we have been told is they are also developing and testing to get approved as a medical device. It’s a work in progress. What it is, is not what it will be. They also purposely chose not to make the current version (not the medical version) not comparable to medical measurements because they keep trying to make it clear that this is not currently a medical device and should not be used as such. Researchers are part of the process and the changes they are making are making it more stable and useful. They are finding different results with ME/CFS then with POTS. They have just rolled out live mode which is a hoot. It is the stand test in real time.

 

[Eddie]

I was interested until I read that!

The images suggest a much more continuous monitoring, so are there different versions of the device? (I may well have misunderstood)

Looks like there are different modes. The real time mode measures every second but presumably uses more power. The website says 5 mins continuous monitoring uses 2% power which doesn't seem too bad.

 

[Murph]

I was interested until I read that!

The images suggest a much more continuous monitoring, so are there different versions of the device? (I may well have misunderstood)

There's the consumer version which prioritises battery life(right in pic) and the test-bed one that runs continuously and produced the charts above (left in the pictire below. It is bigger)




They're also trying to program the consumer one so it starts measuring more intensively when a person is up and about.



I suspect probably people would rather carry more battery and get more detail, especially when the device is new. Honestly it seems like the sort of thing a person would get a ton of value from using for a month to learn their triggers and then the value might fall. I recently wore a continuous glucose monitor for 2 weeks and learned quite a bit about what causes what.

 

[Dolphin]

1-minute video

Here I’m doing a live demonstration of what it’s like to live with POTS (or other forms of OI) using my Lumia. We look fine on the outside, but this is what’s happening inside. Remember blue is my HR and gray is blood flow to my head. Note: Lumia is not a medical device.
#wearlumia #pots #mecfs

https://bsky.app/profile/jessamyn-ann.bsky.social/post/3lihy7vnib227

 

[Murph]

I just joined their facebook group where they are sharing some data from some staff members with POTS. (Seems like they hire people with POTS mostly, must be a weird office!)

I also watched this video



there's an interesting moment where the researcher shows how drinking coffee causes her cerebral flow to rise. I certainly know that diet colas sometimes help me feel way better, perhaps this is why.

 

[Murph]

There's another new video here from Lumia featuring POTS researcher Satish Raj.



it's a bit scrappy, this video, they were tryig to integrate an experiment and an interview and it suffers from not seeming very smooth and professional. but nevertheless it is interesting.

And in this thread a bunch of people shared their data from doing the experiment along with the video.



The 'blood-flow-to-head' effect of pots is so obvious that I think if we could find a link to an immune system effect (e.g. if the brain could call in an immune response if it was deprived of blood sufficiently and for a long enough period) then we'd have a pretty complete theory of PEM, and to explain mecfs altogether we'd need only to go back upstream and explain why blood flow wasn't working. I am very hopeful for discoveries in this area.

 

[wigglethemouse]

Here I’m doing a live demonstration of what it’s like to live with POTS (or other forms of OI) using my Lumia. We look fine on the outside, but this is what’s happening inside. Remember blue is my HR and gray is blood flow to my head. Note: Lumia is not a medical device.

Wow thank you for sharing. That's pretty convincing. How is your view of the Lumina device after some more time using it if you wouldn't mind sharing?

 

[Dolphin]

Wow thank you for sharing. That's pretty convincing. How is your view of the Lumina device after some more time using it if you wouldn't mind sharing?

Just to clarify: I was just posting the text from a Bluesky post.

 

[Jonathan Edwards]

Wow thank you for sharing. That's pretty convincing. How is your view of the Lumina device after some more time using it if you wouldn't mind sharing?

How do we know that this is not a normal pattern for healthy people? If you stand up and use more energy with limbs blood may well be diverted from the head. I have not watched carefully but throughout the video the person shows no signs of distress.

 

[Murph]

How do we know that this is not a normal pattern for healthy people? If you stand up and use more energy with limbs blood may well be diverted from the head. I have not watched carefully but throughout the video the person shows no signs of distress.

The more recent video that I shared includes a person with no dysautonomia diagnosis using the device and that person also shows blood flow to the head falling on standing. So the question of specifically what is different between POTS and non-POTS in terms of the read-out is not yet clear to me!

The theory of it is strong however, the idea for the device is based on van Campen and Visser's detailed work on cerebral flow, including controls:

https://www.mdpi.com/2227-9032/12/24/2566

So there is hopefully something there they can isolate and say: this is the POTS characteristic.

The company is trying to get the device FDA approved as a diagnostic device for POTS so they will have to wrestle with this question specifically, and perhaps publically? (I'm not sure how transparent FDA approval processes are ).

 

[Jonathan Edwards]

The company is trying to get the device FDA approved as a diagnostic device for POTS

The heart rate monitor should indicate POT as per the arbitrary definition. I don't see that it tells us anything about whether the person has POTS, whatever we think that means. Maybe the rest of it comes from the clinical picture but it is all rather vague.

If it shows reduction in blood flow and that is thought to be what is important then the heart rate monitor is in a sense redundant. It does not really matter what the heart rate does if we think it is a useful test of pathologically reduced blood flow. But what seems to me to be missing from all this is evidence that this reduction in flow is pathological in the sense of causing symptoms.

 

[Murph]

The heart rate monitor should indicate POT as per the arbitrary definition. I don't see that it tells us anything about whether the person has POTS, whatever we think that means. Maybe the rest of it comes from the clinical picture but it is all rather vague.

If it shows reduction in blood flow and that is thought to be what is important then the heart rate monitor is in a sense redundant. It does not really matter what the heart rate does if we think it is a useful test of pathologically reduced blood flow. But what seems to me to be missing from all this is evidence that this reduction in flow is pathological in the sense of causing symptoms.

I think they are trying to make the arbitrary heart rate definition redundant! There's wide awareness that cerebral blood flow matters, it's just been a nightmare to measure via transcranial doppler. The HR change is thought to be secondary to the reduced flow, compensatory. The reduced flow is at the core of it.

As for evidence reduced blood flow matters, this is from the company's website:

...multiple studies have empirically demonstrated that drops in blood flow cause symptoms. In this 429 patient tilt table study, Cerebral Blood Flow reductions upon tilting correlated with increased symptoms upon tilting.

It's not perfect data but it might be a clue. I'm hopeful that if enough patients get their hands on these things we might garner some useful hypotheses that can then be tested.

 

[Jonathan Edwards]

As for evidence reduced blood flow matters, this is from the company's website:

That graph is pretty overwhelming evidence that reduced blood flow is NOT the cause of symptoms. A primary main cause does not give a correlation line like that with an R of 0.4. It gives an R of 0.9+.
Interesting to see, because it pretty much trashes the whole story.

 

[Murph]

That graph is pretty overwhelming evidence that reduced blood flow is NOT the cause of symptoms. A primary main cause does not give a correlation line like that with an R of 0.4. It gives an R of 0.9+.
Interesting to see, because it pretty much trashes the whole story.

the great thing about the POTS researchers, and the patients, and this company, and hopefully a few competitors, is they will chug along anyway and we can find out if your view was right.