I found a patent that has a claim that when read out of context could arguably describe my invention. Their claim requires an external device to provide a notification whereas my device recognizes the event itself. Other than that the claim could be stretched to describe my invention.
But when you read the description of the their invention they are definitely describing a different, but similar, system.
The other patent was a refused Japanese patent application.
Given what I have said does it sound like I have to worry about the claim?