Microwave Medical Systems, Inc.

Ciena Corporation

Meridian Medical Systems, LLC

James Regan

Kenneth L Carr

Jeffrey N Weiss

Bappa Sinha

Ed Klein

Ming-Teh Ma

Walter Dray

Dan Cedrone

A system with predefined primary and secondary routes sets up corresponding virtual circuits over both routes. A destination node maintains primary and secondary sets of routing tables that contain, respectively, routing information over each of the rings for every virtual circuit. A destination node disables the appropriate entries in the routing tables for the non-selected route, such that the node ultimately discards the traffic received over that route. To switch a virtual path, and thus all of the virtual circuits included therein, from the selected route to the nonselected route, the destination node disables and enables the appropriate entries in the primary and the secondary routing tables, to switch from using the set-up virtual circuits on the selected route to using the set-up virtual circuits on the non-selected route. To detect an event that triggers protection switching, such as path failure, the system uses &ldquo;Continuity OAM cells&rdquo; to provide path status information to the nodes. A source node periodically originates Continuity OAM cells over the primary and the secondary routes. A node that receives a Continuity OAM cell multicasts the cell to (a) the processor on the node and (b) without alteration to successive nodes on the same ring. If the node processor determines that the node has not received a predetermined number of Continuity OAM cells from the source node over the selected route within a selected number of time windows, the node determines that there is a path failure on the selected route. The affected destination node then triggers protection switching if, in the same windows, the node receives an appropriate number of Continuity OAM cells from the source node over the non-selected route. To facilitate detection of path degradation, the source nodes include error counts for the associated ring interface in the Continuity OAM cells. A destination node detects path degradation when the accumulated error rate over a selected route from a source node exceeds a predetermined maximum. The destination node then triggers protection switching if the accumulated error rate over the non-selected route is better than that over the selected route by a predetermined margin.

Rapid ring protection switching system

A dual mode transurethral warming apparatus particularly adapted to treat benign prostatic hyperplasia includes a urethral catheter dimensioned for insertia through the urethra. The catheter includes an elongated flexible tube having a plurality of longitudinal lumens extending between the ends of the tube. A coaxial cable extends along one of the lumens to an antenna in the form of a multi-turn helical winding wound around the outside of the tube. A first connector connects one of the cable conductors to one end of the winding and a second connector connects the other cable conductor to the other end of the winding so that the antenna formed by the winding is larger in diameter than the cable, and all of the lumens are located within the winding. The cable is connected to a control and display unit which includes a transmitter which provides electromagnetic energy via the cable to the antenna so that the antenna generates an electromagnetic field sufficient to treat tissue adjacent the antenna. The same antenna also detects thermal energy emitted by the tissue thereby developing an electrical signal which is fed via the cable to a receiver in the form of a radiometer in the control and display unit. The cable is connected to the transmitter and receiver by way of a diplexer which separates the transmitter and receiver signal frequencies allowing the use of the common coaxial cable and antenna for both heating the tissue and sensing the actual temperature of the tissue. Preferably, the catheter includes an inflatable balloon at the distal end of the tube, the balloon being inflated by flowing an inflation fluid to the balloon via one of the lumens in the tube. Other working lumens may be included in the tube for providing drainage and for coolant circulation to cool the exterior surfaces of the catheter.

Dual mode transurethral microwave warming apparatus

Infusate warming apparatus comprises a housing defining an internal cavity. A lossy asymmetric transmission line is situated in the housing which transmission line includes an elongated electrical conductor having opposite ends and a conduit for conducting infusate which is highly absorptive to electromagnetic energy of a first frequency through the housing in close proximity to the conductor. A connector extends into the housing for coupling an external electromagnetic signal of the first frequency to one end of the conductor so as to subject the infusate to an energy field which heats the infusate. A temperature sensor for sensing the infusate temperature and controlling the signal to maintain a constant infusate delivering temperature is also disclosed.

Apparatus for controlledly warming low flow rate infusates

Microwave heating apparatus for warming low flow rate infusates includes an electrically conductive housing defining an elongated heating cavity and a printed circuit board which separates the cavity lengthwise into first and second cavity sections. The circuit board includes a substrate which provides a fluid-tight divider between the two cavity sections and a meandering conductor run which extends along the substrate.

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Waltham, MA, United States of America

James Regan