LimbLogic VS

1. LimbLogic VS Amanda Neves URI Biomedical Engineering

2. Lower Extremity Prosthesis • 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

3. LimbLogic VS • 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

4. Components • 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 Charger To AC outlet Vacuum Pump charging port charging plug charger node

5. Gel side of Alpha Liner How to Operate Fabric side of Alpha Liner • 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 Socket Alpha Flex Sleeve Gel side of liner Fabric side of AK Sleeve Socket Vacuum System on/off button

6. Benefits • 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

7. Conclusion • 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

8. Sources • Street, G.M. Vacuum Suspension and Its Effects on the Limb. Orthopädie-Technik Quarterly. (2006): 2-4. Web. 17 Apr. 2010. • 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. 2010. • http://www.owwco.com/limblogic.php • http://www.magnumsystem.com/pr1267.php • http://www.owwco.com/pdf/LimbLogic/LLProsthetistGuide.pdf