Heart rate monitors (HRM) with chest straps are now being replaced by more comfortable strapless HRM, such as UWatch UX. These products are enabled by photoelectric sensors that sample light modulated by blood vessels, which expand and contract as blood pulses through them. One of such solutions is the recently introduced AMS AS7000 including a Cortex M0 core, and a DSP implementing algorithm to process raw photoplethysmography (PPG) readings from the sensors to convert them into digital HRM and HRV (Heart Rate Variability) values.
Highlights of AS7000 Biosensor:
- MCU – ARM Cortex M0 with 4KB RAM, 32 KB EEPROM
- I/Os – 9 GPIOs, UART, SPI, I2C
- Analog electrical and optical Frontends
- Hardware sequencer
- Synchronous detector
- Integrated LEd driver with current control
- Optical filters
- Supply Voltage – 2.6 – 3.6V
- Temperature Range –30 to 70°C
- Package – 18 pins
AS7000 can deliver greater accuracy when it is paired with an external accelerometer, as algorithms can filter out motion artifacts, and maintain high accuracy whether the user is resting or exercising. While the chip is well suited to fitness bands, smart watches, and sports watches requiring several days of battery life, it can also be used in medical sensors, chemical sensors, handheld point-of-care devices, and industrial sensors.
Two evaluation platform are available:
- AS7000 Demo Kit – Complete kit with a display board with PIC microcontroller, a Bluetooth module with a lithium battery, AS7000 and an accelerometer mounted inside a small wristband.
- AS7000 Retrofit board – AS7000 biosensor mounted together with an accelerometer, and cabling that you can somehow use with an existing fitness band.
Both kits comes with a software development kit (SDK), software documentation, and a GUI software allowing users to update AS7000 firmware, as well as the display board board in the case of the demo kit. HRM and HRV readings can be uploaded to an Android smartphone or tablet over a Bluetooth connection.
The AS7000 is available for sampling now, with price starting at $6 per unit for 1,000 pieces orders. The kits’ pricing is only available on request. You may want to visit AMS AS7000 product page for more details.
Jean-Luc started CNX Software in 2010 as a part-time endeavor, before quitting his job as a software engineering manager, and starting to write daily news, and reviews full time later in 2011.