A surgical instrument useful in harvesting blood vessels such as veins and arteries. The instrument has a pair of jaws and a central cutting element displaceable distally and proximally to dissect tissue contained between the jaws. A sequencing element prevents the cutting element from being engaged...http://www.google.ca/patents/US20020099372?utm_source=gb-gplus-sharePatent US20020099372 - Electrosurgical instrument with an operational sequencing element
