The invention provides a nested tubing cannula which comprises outer and inner elongate tubular members, both having a proximal end, a distal end, and a lumen therebetween. The inner tubular member is sealed at its distal end and is nested substantially coaxially within the lumen of the outer tubular...http://www.google.com/patents/US20030187475?utm_source=gb-gplus-sharePatent US20030187475 - Percutaneous catheter and guidewire having filter and medical device deployment capabilities
