Read out sensor data from Bluetooth respiratory sensor to PC?

[Peter Gamma]

On Aliexpress, an affordable sleep tracker is available, which delivers physiological data of high quality:

https://www.aliexpress.com/item/4000016737162.html?spm=a2g0s.9042311.0.0.27424c4d8PccMO

the sensor belt delivers excellent breathing signals, and is very responsive. It should be possible to synchronize data to Apple Health Kith, says the Happy Sleep App. I m not familiar with AHK. And I don t know which data is synchronized to AHK. The belt is paired via Bluetooth to the Happy Sleep app. But no PC app is available.

Is it possible to read out sensor data from this device with Bluetooth sniffer tools?

[CDN_Torsten]

Hi Peter,

My apologies - I don't have an answer for your BT question...

The device is interesting in that it is for under your bed sheets.  Have you tested it's heart rate monitoring accuracy?

I've assuming this belt is an array of pressure sensors which look for change in static pressure to extract breathing patterns and pulse...or is it something else???

Thanks,
Torsten 

[nali]

It'll almost certainly be using Bluetooth LE, so you could use something like Nordic's nRF Connect app to explore the GATT services & characteristics it provides. Some may be standard profiles https://en.wikipedia.org/wiki/Bluetooth_Low_Energy#Health_care_profiles or perhaps it'll be proprietary and/or encrypted - you'll only find out by looking.

[Peter Gamma]

It is a sensor belt. The sensor belt can also be optained separately. I found it on Alibaba. I compared the accuracy to a Polar OH1 sensor, which has ECG accuracy. Heart rate is not so accurate, I estimate about 10 % deviation from a Polar OH1.

But the respiratory signal is of high quality. The signal is very good, and reminds of the  signal of a Bitalino Physioplus Inductive sensor:

https://plux.info/sensors/317-respiration-rip-820202501.html

Do they use the same sensor belt?

Can the Adafruit Bluetooth sniffer be used to read out sensor data?:

https://www.adafruit.com/product/2269

[CDN_Torsten]

I have no experience with this product...just find it technically interesting.

I would agree with nali - try the "nRF Connect for Mobile" phone app first to see what the belt is transmitting.

[Peter Gamma]

thanks for your answer. Here is the belt from alibaba:

https://german.alibaba.com/product-detail/taidacent-smart-mattress-breathing-sleep-belt-heart-rate-respiration-sensor-espiratory-heart-rate-piezo-restive-pressure-sensors-60856585653.html?spm=a2700.galleryofferlist.normal_offer.d_title.5abc48beJburZP

Scott Harden, PhD. said, the Alibaba belt could be used with his sound card ecg device when the ecg break out board is replaced by the belt (roughly):



but the sleep tracker already has a Bluetooth module. Is it no easy for the manufacturer to make a respiratory sensor out of it? It only needs a Matlab or Python inferface, or a .csv export of the Happy Sleep app.

Or hacking the Bluetooth signal?

[nali]

Re: sniffing - possibly. You'll only find out by trying. Even so, the data payload may be encrypted although if it will interface with other apps probably not.

Note you'll only be able to sniff when you have app actually connected & reading data from it, otherwise all you'll see is a shedload of advertising packets.

As I said, you'll only find out by trying so the only person who can really answer is you - by buying a sample, connecting it and sniffing. Everything else is merely speculation.

[Peter Gamma]

Unfortunately, I cannot do it, since I don't have the time. I'm only interested in this project and promoting it:

https://forums.adafruit.com/viewtopic.php?f=19&t=175668

[Peter Gamma]

James Clutterbock, devleper of the Mind Monitor app said, he does not want a cloud connection, since he does not want brain data in the cloud. How is it with the Chinese developer of the sleep tracker and privacy? Does he encrypt heart and breath data? Unfortunately, they don't have a forum, where this can be discussed.

[Peter Gamma]

The sensor belt appears to be solid made, according to the video on Alibaba:

https://www.alibaba.com/product-detail/Taidacent-Smart-Mattress-Breathing-Sleep-Belt_60856585653.html


there was once a demo video available on Alibaba of a person using this sensor and testing it. He was showing the sensor data on the screen. So the manufacturer must have PC software for this belt. Will there be a commercial product some day?

Unfortunately, it is not possible to ask questions on Alibaba for me personally, since I am not a reseller, It is only possible for sellers. Maybe a reseller is interested in this product? I only saw it on Alibaba.

An Adinstruments setup with respiratory belt and software is around 2000 USD, estimated, and  non-wearable:



There are several respiratory sensors available from Bitalino Physioplus, starting from USD 100. There are models available, for 400 to 600 USD, the prize depends on the bit rate, the Bitalino support told me. And there is a complete respiBAN Professional available:

https://plux.info/biosignalsplux-wearables/313-respiban-professional-820202407.html

But all of these devices depend on microcontrollers. Since the availablity of the sensor belt with a Bluetooth transmitter, it is not far ahead for a consumer product for everyday use at an affordable price.

But the only one which can do this is the Chinese manufacturer Taidacent, which has all the components.

The second option would be to build it yourself with the sensor belt and Scott Hardens, PhD circuit. Scott gave the green light for it.

Or maybe another device developer is interested in developing a respiratory sensor device, and negotiates with Taidacent about these components?

Is it not a pitty, that all the components for an affordable respiratory sensor for everyday use are available, but nobody brings such a device on the market?

[Peter Gamma]

I forgot to mention the Adinstruments Equivital, which is wearable:

https://www.adinstruments.com/partners/equivital

request a quote for this product, and book a demo. The warranty time for this product is a far as I know 3 month.

[Kean]

Shenzhen Taida Century Technology Co ("Taidacent") is just a small manufacturer/reseller of electronics parts.  Looking at their product range, I do not think they have developed this product you mention, but they may helped to manufacture it for someone else.  On Alibaba they just seem to be selling the sensor belt without electronics.  It appears to be an array of piezo vibration sensors of some sort, probably just wired together as one long vibration sensor.  I imagine it would require a bunch of signal processing (analog and digital) to get anything useful out of it.

I wouldn't be surprised if they have just happened to come across some old/excess stock of the belts and thought they could sell them off at a profit.  This is pretty common.  They will happily sell you a couple of the belts for ~US$210 if you want to plug them into something of your own devising.  I suspect this is old/excess stock as the price for the complete Bluetooth smart belt you linked on the AliExpress "Healthy Store" is lower (US$85) than the individual sensor belts without electronics on Alibaba.  And I am pretty sure neither of those sellers would know how the actual monitoring stuff or BT protocol and app is implemented.  They just sell the parts, someone else wrote the firmware & app.

There is a reason "trusted" commercial products like this cost a lot of money - there are significant R&D costs and a small market to sell to.  You could spend months trying to get this sensor or device to partly work, and then find you can no longer buy the parts or that it doesn't actually work reliably.

Sorry to be blunt, but I really think this is not the right forum for you.  Your topics do not really belong in the Test Equipment section, and they possibly don't belong here at all if you do not have the background to do anything with the responses.  I'm also thinking about your recent post querying the use of uncertified EEG "demo kits" on human subjects, and some prior topics where several of us tried to help but eventually gave up.

[Peter Gamma]

Thanks Kean for your answer.

I don t know whether the sensor belt is a stock sell out. I saw it since I guess a year or more on Alibaba. There was a demo video of someone who did experiments with it.

Now, there is a sleep tracker which is based on a sensory belt on Aliexpress, which is about the same prize as the sensor belt on Alibaba. I doubt this is based on a stock sell out.

Also Bitalino had first only one sensor belt for around 100 USD. Then they had a new one for about 300 – 400 USD, which they said is less sensitive to motion artifacts. They have  two models, one with a 8 bit microcontroller, and one with a 16 bit controller.

Warranty time of Bitalino sensors is a year. But when I look at the sleep tracker sensor: it has no warranty time. And when I imagine to sleep every night on this sensor, I don t know who long it will survive. I could not find any user reports demonstrating a respiratory belt using 24*7 over a longer period of time. Respiratory rate estimation in Matlab which is based on R-R peaks could be an alternative.

But one option could be to tear down a sleep tracking sensor and to find out, whether it is possible to connect it to Scott Hardens circuit and software. The costs for this setup is around 100 – 200 USD. When I look at the signal quality of the sleep tracker respiratory signal, it apears to be comparable to the newer Bitalino belts. But the signal is boosted by the software, and don t know for shore. 

[Peter Gamma]

What the TI EEG board is concerned, I retreated from this question, since there are other products on the market, which are more attractive to me personally than the TI EEG board. In my view, the problem is, that it is difficult to sell software and hardware for EEG or respiratory devices.But I think these devices are too little developed. If more research is done, more applications are available, and these new sensors can become part of our daily lifes.

 The best products I could find where those for instance from Scott Harden etc., which developed those for fun and in their spare time. 

Manufacturers start to complain that they only have an income from selling these products, what can I do?

Like in a herd of cows, they copy each other, starting post deletion, inactivating user accounts, and starting complaining about a poster. I m currently trying to get my Matlab posts back, since the deleter was a very superficial reader, and I think I have good arguements to bring those back. 

[Peter Gamma]

@ Supporter Kean

Swiss quality seller Digitec sells a sleep tracker with a sensor belt for 111 Fr, which is 122,39 USD , with a belt which looks identical to the sensor belt sold on Alibaba:

https://www.digitec.ch/de/s1/product/sleepace-reston-wecker-8589056?gclid=Cj0KCQiAst2BBhDJARIsAGo2ldX74p5bP3Cb5jWweOTDWrJhTeA2V_RSNUhZ3WCmiYraVu848oq2hmgaAllmEALw_wcB&gclsrc=aw.ds

It can also track respiratory signals. Therefore, I suppose it is not a stock clearance. And if it is all the same a stock clearance of the Sleepace RestOn, the Sleepace RestOn is currently sold for 122,39 USD. This suggests, that the hardware costs for these sensor belts have dropped strongly.

[Peter Gamma]

Withings Sleep Analyzer for ca 100 USD at digitec Switzerland also has a belt which tracks respiratory rate:

https://www.theguardian.com/technology/2020/jun/25/withings-sleep-analyzer-review-advanced-sleep-tracking-made-easy

Is Withings Sleep Analyzer also a stock clearance? This is not believable.