From Google safety guide:
Your device uses components that may emit electromagnetic fields, and also contains magnets. These electromagnetic fields and magnets may interfere with pacemakers and other implanted medical devices. Always keep the Nest Cam Stand at a safe distance away from pacemakers or other implanted medical devices.
What is a "safe distance?"
Thanks for reaching out. If you have questions about using your Google device with or near your medical device, consult your healthcare provider before using your Nest Cameras. If you suspect your Nest Cameras are interfering with your medical device, turn off your Google device and consult your physician for information specific to your medical device.