Muse 2 won't turn on



I’ve been using the muse successfully for a while but this morning I had a problem connecting via bluetooth so I killed the application while the connection process was underway, turned the headset off and restarted the app. However, the headset now won’t come back on. I have charged it for several hours (while I went to work) and the charge light is on solidly but not matter how long I press the power button the headset won’t come on.

Any suggestions on how to reset/restart the device ?