Our new online store is udevices.io

October 25, 2024

At the end of 2023, we found out that Tindie blocked sales from Ukraine, so we moved our shop to Etsy. However, it was blocked there almost immediately and we paused sales after that.

After a break, we opened a new online store. It's a standalone shop based on Shopify, so we no longer depend on a marketplace.

You can buy uECG here in our new shop: https://udevices.io/products/uecg-single-channel-wearable-ecg-sensor

Thank you very much for your support and patience!

We'll be glad to see you in our Discord community - https://discord.gg/dEmCPBzv9G

Changelog for uECG v.4.52:

• Replaced AD8606 op amp with a pair of TLV271s;
• LDOs (3.3V for digital, 3V for analog side) were mixed in the previous version; strangely this didn’t affect functioning, but now this is fixed;
• Replaced BMI160 with LSM6DS3TR-C;
• Changed C6 capacitor from 2.2uF to 10uF for better low frequency performance;
• Replaced circuit protection (red LED) with diodes for more reliability;
• Changed charge resistor to 8.2K Ohm to fit the battery charging better;
• Replaced MCP71831 charger IC with TP4054;
• Added thermistor for measuring temperature;
• Changed RGB LED to different part number;
• Added Ultimate Robotics logo on the back of the PCB.

November 26, 2022

We have launched our second device, uMyo! It's a single-channel EMG sensor with both wet and dry electrodes. You can check it out here. Also, we wrote a small post about the blackouts in Ukraine (which you've probably read about in the news) here. Check it out, bet you've never seen anything like this.

June 10, 2022

We have reopened uECG sales today (and a large firmware update)

June 7, 2022

A tribute to our friend, veteran and fellow maker, Denys Antipov

March 17, 2022

War update #2 (volunteering and living from day to day)

Feb 28, 2022

War in Ukraine (that's where we are) update

User manual and troubleshooting: Instructions on Hackaday

Code and hardware: Github

Vlogs, teasers and videos on all of our projects: YouTube channel

We post a lot of updates, videos, reels and pictures of the process on our Instagram

Our fb blog (in Ukrainian): Facebook

What is it?

It’s an open source hardware wearable ECG sensor that can be used as a development platform, a research tool, or as a standalone device. We made uECG for everyone, and it will be most useful to researchers, students, developers, makers and healthcare professionals.

We’re a team of four people from Ukraine and we’ve been developing uECG since 2019. We try our best, but it’s still more a device for development or research than a consumer product. We 3D print our device cases, do final assembly manually, and ship devices ourselves. However, we test and thoroughly check everything, so the devices we ship are made to the best of our abilities at the moment. We also provide support to all buyers (and non-buyers too :). We’re always developing and improving our technology, production and shipping, so there’s going to be more updates all the time!

Main features:

• 1-channel ECG (1 channel + 1 GND electrode)
• Real time processed ECG signal streaming + csv export of raw data
• Stream to smartphone (Android) or PC (via USB base receiver); more on software in Software specs below
• Can be also used with existing fitness apps (standard BLE connection)
• BPM, HRV, Poincare plots
• Accelerometer/gyroscope data
• Wireless firmware update
• Lightweight - sticks on the chest via 2 electrodes; compatible with ECG chest straps (through adapter)
• Low noise - can be used while running or working out
• 24h battery life in streaming mode
• 3D-printed case in 5 colors (black, pink, yellow, turquoise, and white)

Hardware specs (v.4.52, March 2023)

• Microcontroller: nRF52832 BLE SoC
• ADC: MCP3911 dual channel
• Buffer op amp: 2x TLV271
• IMU: LSM6DS3TR-C gyroscope/accelerometer (low noise, 16-bit)
• Short circuit protection: yes; PTC resettable fuse
• Antenna type: 2.4Ghz, IPEX1 connector
• Antenna gain and size: 5dB (sticker type, 35*11mm)
• Battery: 220mAh lipo, 501245 size
• Charging: micro USB type B
• ECG snap connectors: 3.9mm diameter (compatible with most disposable gel electrodes)
• Weight: 15.3 grams (with battery, antenna and 3D-printed case)

Software/firmware features:

Connection. Works as generic pulse metering device with fitness apps, uses our custom BLE protocol for ECG data transfer, and custom RF protocol for streaming to PC at 1 kHz (using our USB receiver base).

Signal filtering. Noise filtering algorithm is used to remove 50/60 Hz noise from ECG signal while keeping high frequency components of ECG.

Signal processing. Android app calculates BPM, HRV, GSR and RR interval, displays accelerometer data, and builds Poincare plots. Similar functions also available in desktop app. Onboard firmware can also process and stream both ECG and EMG signal.

Platform support. Our Android app is used to receive data on smartphone, analyze it (using graphs and Poincare plot function) and store raw data as .csv files. It is also used for wireless firmware upload. For desktop PC, our node.js monitor app is available on Linux/Windows/macOS systems. uECG is also compatible with most fitness apps (app sees it as generic heart sensor).

Multi-device support. Up to 8 uECGs can send data simultaneously to desktop app via USB receiver base - USB base RF protocol has discovery function for all devices in range, and low latency.

Firmware update. Firmware update. Wireless firmware update via Android app is now possible! This requires new bootloader though - so older (pre-September 2020) uECG units require bootloader update via STLink v2 to support this feature.

Standard kit (1 uECG) contains:

• uECG device in a 3D-printed case (in chosen color)
• 10x disposable gel electrodes (45mm diameter)
• micro USB cable for charging
• 3x replacement screws for the 3D printed case
• user manual

Optional:

• USB receiver base (for streaming to PC)

This adds PC connection capabilities. With it, you can stream to a lot of platforms. You don't need it if you will only stream to smartphone/Android.

• STLink v2 USB programmer

These are legacy. You don’t really need it now, because we recently implemented a wireless firmware update. You only need it if you want to edit the bootloader or use your own. Or if you just need an STLink for programming something else. We use them for our nRF and STM32 based projects.

• up to 20x additional gel electrodes

We would sell more, but it’s hard to fit more of them in the package, we honestly tried… also, we began running out of them too fast to restock on time. In any case, 10x free gel electrodes will always come with each uECG, so you can have up to 30 this way.

Note: if you need several uECGs, but you only need one receiver/one STLink/one set of additional electrodes per your order, then you should first add to cart one uECG with the necessary options, and then add more uECGs with no additional options, otherwise you will add the chosen options to every uECG and it may be not what you want.

Some additional info on gel electrodes

You can use any gel electrodes, disposable or not. We use 45mm because larger diameter intersects with each other (and we don’t want to make uECG longer, at least for now). This doesn’t influence the signal. So standard 50mm (or even larger) will work too, if you’re okay with them sticking over each other a bit or cutting them slightly. The 45mm gel electrodes we order are solid gel type and are produced by a medical supplies manufacturer in China. We quite like the quality for the price. Except diameter, one other thing you may want to look for in electrodes is breathability. If they have textile-looking substrate (like ours in the pictures), they can be worn better during physical activities or just for longer time. Oh, and they stick better on hair, cause they are more flexible and thin. If, on the other hand, the electrodes you found have a solid, thick and soft white base, they may not be as breathable, but may work better for your specific case. You may want to experiment or read on that, but what really matters most is: 1) diameter 2) type of gel 3) substrate, which will ultimately determine how well they will stick on you and how noisy the signal will be.

Looks like that’s all the info we could think of. If you want to read more (and our project logs), our Hackaday project page is the best source. Also, feel free to message us in case you have a custom request!