EYE ON NPI - ams OSRAM AS7038RB Biosensor Solution with Embedded ECG Channel @amsosram @digikey
Channel: Adafruit Industries
Date: 28/04/2022

This week's EYE ON NPI is getting fit and staying healthy, with ams OSRAM's AS7038RB Biosensor Solution with Embedded ECG Channel (https://www.digikey.com/en/product-highlight/a/ams/as7038rb-biosensor-solution). This all-in-one biological sensing and health sensor combines an optical PPG (https://en.wikipedia.org/wiki/Photoplethysmogram) pulse oximetry sensor (https://en.wikipedia.org/wiki/Pulse_oximetry) with electrical ECG front end (https://en.wikipedia.org/wiki/Electrocardiography) as well as skin temperature reading with a low cost NTC thermistor, and conductivity - a.k.a GSR - so you can get a lot of heart and blood health information in one convenient package.  This is very nice and cost-effective as usually there's one sensor to manage the optical blood-gas sensing and one to do the electrical heart activity sensing and maybe other sensors for skin temperature and conductivity.  However, for telemedicine or self-monitoring, it might be beneficial to see the electrical activity waveforms as well as the SpO2 measurements since they can signify different health issues.

Even though we are highlighting the AS7038RB (https://www.digikey.com/short/mjq0vjrn) we also want to point out the AS7030B (https://www.digikey.com/short/z308w2wr) which is a 'modularized' version of the 'RB but with a plastic body and three emitter LEDs for an even simpler installation. We're particularly fond of any PPG sensor that has both the emitter and detector diodes built into the package, it makes sourcing and tuning a lot easier!

With the proliferation of smart watches and wristbands, many are now including optical sensors on the bottom - and this sensor is a great way to add that capability to your design without a ton of extra components or work. Pulse oximetry, especially, has become an essential home measurement for folks who have COPD or have tested positive for COVID as low blood oxygen and high pulse rate indicate cardiovascular damage that sometimes the patient doesn't even notice (https://en.wikipedia.org/wiki/Silent_hypoxia). A full time wearable PPG using the AS703x would be great for detecting hypoxia even if the patient forgets to check their pulseox.

This sensor comes jam packed with many built in filters and configuration registers to tweak the LED current, optical sensor gains, low pass, high pass, offset and drift reduction. This is usually the hardest part of getting PPG/ECG data in a pure-digital system: filters and offsets can be easy to implement in analog-land but annoying for a microcontroller to continuously calculate while also trying to stay in a low power mode. Instead, that work is done so that clean data can be read from I2C directly when ready.

There's also a Feather-friendly eval board available for purchase (https://ams.com/as703x-eval-kit), with a built in Particle Argon Feather board for fast IoT prototyping using the default ams Windows application. The app lets you tweak and set various values and gives some good starting points, especially for customers with different skin tones!

Sounds great, right? If you wanna pick up the ams OSRAM AS7038RB Biosensor Solution with Embedded ECG Channel (https://www.digikey.com/short/mjq0vjrn) It's in stock right now at Digi-Key, for immediate shipment! Order today and you can be PPG-EKG-GCR'ing to your heart's content (ha!) by tomorrow afternoon.