We are building a wearable device (necklace form factor) that requires the ability to detect falls.
We decided that a 3 axis accelerometer would give us all the data necessary for human motion/fall detection from a necklace form factor.
We were originally looking at the ADXL362 for its low power, small size, free fall interrupt. If we select this chip then we can wake up our MCU on freefall and then use the MCU to poll the accelerometer for the impact event. We then found the ADXL345 which allows you to set thresholds on both the free fall and the impact so that our MCU will only wake up for a true human fall.
Rather than dig through any more data sheets, I was hoping that someone could provide input on whether the ADXL345 is the optimal chip for human fall detection, or if there is something newer and better (looks like the ADXL345 is about 4 years old?)
We are also using the accelerometer to measure motion of the device (activity level of the person wearing it) - we are waking up the mcu and polling the x,y and z for this activity level measurement. Another item that we would like to incorporate is identification of "near-fall incidents" - we have not yet tested to see how reliably near-falls can be detected, but it's something we are considering.
Any help is much appreciated.