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AFE4403EVM Wrist Heart Rate Detection

Mike Pena
Prodigy 30 points
Other Parts Discussed in Thread: AFE4403EVM, AFE4403

I'm looking to design a wrist based heart rate monitor using the AFE4403. I have been working with the AFE4403EVM for the past few days with little success. I have been able to detect the heart rate on my finger, but not on the wrist. I looked through the forums and found a post saying to use a laptop on batteries to reduce 60Hz noise. I did this but still didn't have much luck. 

I also tried the Enable Calibration Routine on the ADC Capture & Analysis tab but this didn't help either. What does this do? Is it supposed to actively monitor the signals and adjust the current and gain accordingly? If not, is there something that will do this? Or does anyone have some settings that worked on the wrist that I could use to get started and tweak the Current, Gain and Timing from there?

  • 0
    TI__Mastermind 18285 points

    Mike,

    The TIA gain (Rf), TIA bandwidth (Cf), LED current (ILED), second stage gain etc has to be programmed such that the signal quality at the ADC output is reasonably good for extracting the heart rate value out of it.

    The AFE configuration normally is unique for every individual. But we tested both the sensor boards shipped with AFE4403EVM kit on multiple individuals and came up with the configuration. This is the default GUI configuration.
    This configuration will work on most of the users but we cannot make any guarantee.

    Alternately you can enable the calibration routine in the GUI to take the aid of the gain calibration algorithm to find the appropriate setting for TIA gain and LED current to get to ADC mid-range.