Abstract: A phototherapy method for assisting the transvenous lead placement for cardiac resynchronization therapy (CRT) and dilation of occluded veins for any implantable lead placement. The phototherapy treatment helps increase blood flow, reduce inflammation, and enhance angiogenesis to facilitate optimal positioning of the leads.

Abstract: In a system having a plurality of nodes such as Ethernet repeaters, coupled by communication links such as cables, systems and protocols are provided for detecting and/or breaking loops. In one aspect, in response to an added link, a repeater sends a “detect loop” message containing its address to at least one neighbor. Each repeater which receives the “detect loop” message, in turn, sends it to its own neighbor, with the lesser of the received address and its own address. A repeater which receives a “detect loop” message containing its own address declares itself a master loop breaker and can isolate one of its ports to break the loop. In one aspect, a previously intentionally-isolated port can be re-activated, e.g., in response to the loss of a communication link which could potentially isolate one or more nodes.