Abstract: An intervertebral disc implant (10) includes an envelope (12) of a stretchable and elastically deformable elastomeric material. The envelope includes an attaching formation (74) for attachment of an introducer (76) to enable the envelope, in a collapsed state, to be introduced into a volume of an intervertebral disc that has undergone a nucleotomy. A filler material (14) is receivable in the envelope via the introducer to cause the envelope to expand elastically to conform substantially to the volume in which the envelope is received.

Abstract: A planetary gear apparatus that includes a pair of internal ring gears (24a, 24b) interconnected to be driven together, a pair of planetary gear assemblies (25a, 25b) each associated with a respective internal ring gear (24a, 24b), and each comprising plural pairs of planet gears (48, 49), where each pair of planet gears (48, 49) has an outer planet gear (48) in mesh with the respective internal ring gear (24a or 24b) and with its inner planet gear (49); and a pair of sun gears (27a, 27b) each associated with a respective planetary gear assembly (25a, 25b).

Abstract: A device (10) for evaluating dynamic, mechanical properties of materials includes an elongate cylindrical housing (12) projecting from a handle (14). The housing (12) defines a passage (16). One end of the passage (16) is closed off by a plug (18) with an opposed end of the passage (16) having an end cap (20). A resiliently flexible beam (22) is arranged in a cantilevered manner in the passage (16). A probe (24) is arranged at a free end of the beam (22). A strain gauge array (28) is mounted on the beam (22) for monitoring the deflection of the beam (22) and for generating an output signal representative of the movement of the beam (22). A method for evaluating dynamic, mechanical properties of materials is also disclosed.