Amanda Neves URI Biomedical Engineering

 Fit of the prosthesis is extremely important for the comfort of the limb and prevent skin irritation or pain  Typical attachment systems: ◦ Pin Lock ◦ Cuff (strap)  Relatively new method is vacuum suspension  Commercially known as LimbLogic VS by Ohio Willow Wood  First created and tested in 1999

 Suction method works by altering the pressure the limb experiences between the socket and liner  Prevents volume loss in the limb throughout the day that typically makes wearing the prosthesis uncomfortable and loose  Using vacuum system rather than pin lock system makes the artificial limb feel lighter and the connection between the limb and the socket is much stronger

 Vacuum system includes a pump that removes air molecules from sealed air space between socket and liner  Vacuum level is regulated and set custom to every patient  Battery is included that will last the life of the product  Vehicle power charger is available Vacuum Pump charging port Charger charging plug charger node To AC outlet

 User will roll a sleeve (Alpha Flex Sleeve) over socket and top part of folded over liner to ensure an airtight gel-to-gel connection  When the wearer is ready for the pump to begin regulating the vacuum, they’ll press the on/off button  The pump will operate until the preselected vacuum level is reached and then shut off  To turn off the pump if necessary, the on/off button will be pressed two times and the vacuum will vibrate twice on/off button Socket Alpha Flex Sleeve Fabric side of Alpha Liner Gel side of Alpha Liner Socket Fabric side of AK Sleeve Vacuum System Gel side of liner

 Skin and liner are not able to separate from the socket, improving the limb health  It would take an extraction force of 70kg to cause any separation between socket and liner  Since everyday activity rarely exceeds 5 to 10 kg extraction force, there’s little chance separation will occur  The secure connection improves wearer’s control over leg  New users are surprised at how closely prosthesis feels like part of their own limb  LimbLogic VS is now completely waterproof for freshwater up to 12 hours, and the amputee can go up to 10 feet

 Ohio Willow Wood launched this system for commercial use in September 2007  Was met with overwhelming positive response from both practitioners and patients  Educational and demonstration classes are offered for both practitioners and technicians to help better understand the product and spread the word  This new vacuum system is making prosthetic legs more comfortable than ever for amputees Conclusion

 Street, G.M. Vacuum Suspension and Its Effects on the Limb. Orthopädie-Technik Quarterly. (2006): 2-4. Web. 17 Apr  Beil, Tracy, G.M. Street. Comparison of Interface Pressures with Pin and Suction Suspension Systems. Journal of Rehabilitation Research and Development. (December 2004): Web. 18 Apr    osthetistGuide.pdf