Patent attributes
A plurality of nodes are connected to a network. A first node converts the image signals into image signal data and transmits the same. A second node converts the biological signals into biological signal data and transmits the same. A third node receives the image signal data and the biological signal data. A master counter is provided in one of the nodes to provide a reference count. A first counter in the first node appends a first count to the image signal data. A second counter in the second node appends a second count to the biological signal data. At least one of the first and second counters issues a query to the master counter to receive the reference count as a response. At least one of the first and the second counts is corrected, based on the reference count and a time period from the issuance of the query to the receipt of the response, so as to synchronous with the reference count.
