Abstract: A process for treating biological tissue prior to implantation to mitigate the calcification of the tissue following implantation comprises incorporating acetylsalicylic acid into the tissue in an amount effective to reduce calcification of the tissue after it is implanted. In accordance with one embodiment, the process involves convalently binding the acetylsalicylic acid to the tissue via a coupling agent.

Abstract: A system detecting the presence of successive drops of fluid in a fluid path has a system input for connection to a photoelectric transducer so situated as to have a change in electrical output on the presence of a drop in the fluid drop path. The system includes an arrangement for storing a quantity related to the value of the photoelectric transducer output in the absence of a drop. The quantity stored can then be compared with the present value of the output of the photoelectric transducer, and in the event of a sufficient difference, an output may be provided. In a preferred embodiment, the output signal itself may be used to disconnect the storage system from receiving input information that pertains to the presence rather than the absence of a drop.