Abstract: Systems, devices, and methods are operable to track usage of a surgical instrument and modify the performance of the surgical instrument based on the prior usage of the surgical instrument. Some surgical instruments are designed to have a limited service life beginning at their first use, or a limit to their overall usage in order to ensure safe use of the sensitive instruments. However, a lack of ability to track usage characteristics when the instrument is separated from an external power supply allows for user abuse and avoidance of such safety mechanisms. Adding a battery or capacitor to the instrument may allow for an ability to track usage when the instrument is separated from an external power supply. Implementing special user prompts, device use ratios, and device use half-life upon powering down of an instrument may additionally be used to prevent circumvention of safety features.

Abstract: A string for sports application, in particular for tennis, badminton, racquetball and squash racquets or the like comprises a center core and at least one ribbon-like wrap made of a highly abrasion resistant material which exhibits a higher melting point and at least one of a higher dynamic stiffness and a lower static stiffness than the core material. A preferred wrap material meeting the above criteria is poly(m-phenylene isophthalamide). The wrap should cover at least 25%, and preferably at least 50% of the center core's outer surface to reduce notching. Due to the reduced notching, superior combined properties of durability, playability and minimal loss of string tension are achieved.