Heartbeat rate detection only a heartbeat away

Algorithm Demo

Avnet's vital signs detection algorithm can automatically screen out non-living objects and extract valid data. In the video demonstration environment, the author is located 1.32 meters in front of the radar. When the sweep bandwidth is 5GHz, the corresponding range index is 44. The upper left image in the video is the breath range heatmap of the entire space. The horizontal axis is the radial distance of the target to be measured relative to the radar, and the vertical axis is the detected breathing frequency.

Cfar on heat range heatmap is an effective target selected by the constant false alarm algorithm. The location of the mouse cursor signals the coordinates of the author's position. The respiratory rate is about 23 times per minute. At the beginning of the video, the author breathed normally. Between 00:31 and 01:20 the author held his breath, and you can clearly see that the breath disappeared from the video. This algorithm can automatically eliminate the invalid data caused by the slight shaking of the target, and prevent it from being measured, improving the validity of the data and the accuracy of the measurement results. Because the author needs to operate the mouse remotely, slight movements of the body will impair the accuracy of the measurement. The algorithm can automatically identify and discard data contaminated by slight movements. In addition, the numerous strong reflection interference objects in the author’s office environment, such as metal window frames, chairs and so on, have been automatically filtered out by the algorithm. Here are some screen shots from the demo video.

Comprehensive Effect Demonstration

The upper left image in the video can be interpreted as an image of the displacement of the chest cavity caused by breathing. The author's respiratory rate is 23 times per minute. At 01:06, the author started to hold his breath, the breath weakened, and thus disappeared. The bottom left image is the time-domain waveform of the heart rate. The bottom right corner is the text printed information. We can clearly see the author's steady breathing signal, and we can see the steady signal output from the lower right corner, including distance dimension, respiratory frequency, and heartbeat rate information.

Conclusion

Avnet’s vital signs detection algorithm offers these significant benefits:

1. The algorithm can run on universal ARM processors, greatly reducing product costs.
2. The algorithm automatically filters non-living objects in the radar detection range, so that the product is not restricted by the environment.
3. The algorithm automatically filters the respiratory and heartbeat rate data contaminated by the movement or slight movement of the target to be measured, thus improving the accuracy of measuring the respiratory and heartbeat rates.
4. The algorithm can detect multiple signs of life at the same time, thus providing a tool for seeking multiple targets in the same space.

The evaluation board has started to receive applications in February 2021. Contact your Avnet sales representative for more details. For algorithm and technical details consultation, please contact us.