Patent ID: 7331950

Claim:
A surgical system, comprising: a pneumatically powered surgical instrument, and a hose assembly configured for engagement with said pneumatically powered surgical instrument, the hose assembly including, a first conduit having an inner wall portion concentrically and adjacently arranged with an outer wall portion, the inner and outer wall portions being of at least a first and a second dissimilar material, the first conduit at least partially defining a first fluid path for the transmission of exhaust gases from the surgical instrument, the first conduit having a first cross-sectional area for fluid flow, a second conduit at least partially disposed within the first conduit, the second conduit at least partially defining a second fluid path for the transmission of a pressurized fluid to the surgical instrument, the second conduit having a second cross-sectional area for fluid flow, and wherein the first cross-sectional area is substantially greater than the second cross-sectional area and the first dissimilar material forming the outer wall portion of the first conduit has a first flexibility and the second dissimilar material forming the inner wall portion of the first conduit has a second flexibility less than said first flexibility such that the first and second dissimilar materials forming the first conduit create a discontinuity in the material properties generating an acoustic impedance mismatch that absorbs noise generated by the pneumatically powered surgical instrument.