Helmet system and methods

A method comprising:

• in a first mode:
• with an optical sensor coupled to and defining a field of view extending outwardly from a posterior end of the helmet, capturing a second video frame at a second time;
• storing the second video frame with a first sequence of video frames in local memory in the helmet, the first sequence of video frames captured over a period of time corresponding to a buffer duration;
• in response to capturing the second video frame, removing a first video frame from local memory, the first video frame captured at a first time preceding the second time by a duration exceeding the buffer duration;
• and
• at approximately the second time, rendering a subregion of the second video frame on a display arranged within the helmet;
• in response to detection of an accident involving the helmet, transitioning from the first mode into a second mode;
• in the second mode:
• with the camera, capturing a second sequence of video frames;
• and
• storing the second sequence of video frames in local memory in the helmet, the second sequence of video frames corresponding to a period of time exceeding the buffer duration;
• and
• assembling a video file comprising the first sequence of video frames and the second sequence of video frames stored in local memory;
• and
• uploading the video file to an external computer system.