Abstract: One embodiment of the invention provides a perfusion system including: a first circuit adapted and configured to circulate a first perfusate through a lumen of a small intestine and a second circuit adapted and configured to circulate a second perfusate through one or more blood vessels of the small intestine. Another aspect of the invention provides a method of perfusing at least a portion of a small intestine. The method includes: circulating a first perfusate through a lumen of the small intestine and circulating a second perfusate through a blood vessel of the small intestine.

Abstract: An optical communication system has a transmitter that generates an optical signal containing payload data and security data. The transmitter double modulates an optical signal where payload data is in-band and security data is out-of-band. If a man-in-the-middle attack occurs and the intrusion device is unable to detect the out-of-band signal, the intrusion device will not replicate the out-of-band signal thereby allowing the presence of the intrusion device to be detected.