SleepWyzely
A project to see if a the Wyze can be used for sleep monitoring. The infrared imaging capability, streaming output, and cheap price make it an ideal device. The fact that this operates by using a video camera makes this an in-ideal device. Still makes for an interesting challenge.
Project Setup: I used a Wyze security camera to capture my sleep from the vantage point of my night stand pointed at the center mass of my chest. I used an SD card to record the night of sleep for processing. I am in the works on using the RTSP stream and processing real-time as well, possibly to a dedicated phone app for ease of use.
Processing: I used opencv to give me the raw data for Julia to process. I take the first frame as a keyframe and calculate the difference of each subsequent image as a percentage. If the percentage gets too high (meaning I am moving a whole lot) I skip some data and take a new keyframe image. The movements do not allow for accurate calculation, which is why I skip some data. This process produces a CSV file with Time (Approximate based on 10 FPS stream) and the Count which is the percent of image difference from keyframe.
Post-processing: I load the CSV into Julia to get the actual estimation. I smooth the data with a running average on the count. Depending on how I am positioned I get varying accuracy and sinusoidal amplitude. I used Pluto to play with the data and got within the realm of reasonable results.
Smoothed Sample of data. I use a simple peak finding package to get the distance between breaths in frames and use that to solve for time. The 10 FPS makes for easy conversion.
Full Results
Future Plans:
- Implement the code to run real-time and push results to a server for storage
- Create a CLI tool to provide the same functions
- Use flutter to make an app for fun
Other Methods: I had attempted to use, but failed to make work using DFT to calculate the breathing rate, but I ran into some issues finding the peak signal reliably. There is some low level module and compression noise that makes it a bit hard, but I am sure that someone with more signal processing skills could do it no problem.