Abstract: This invention relates to bioprosthetic heart valve stents that are fashioned of bioresorbable materials. Such stents may be configured as sheaths or frames contoured to the shape of a valvular graft. The stents are eventually resorbed by the patient, leaving a functional "stentless" valve with improved hemodynamic characteristics compared to stented valve implants.

Abstract: A frequency surveillance method for monitoring background atmospheric noise evels in unoccupied channels in an operating frequency band of a high frequency communication system. In the method, the unoccupied channels are scanned a number of times to obtain analogue signals. The obtained signals are transformed to a digital form and averaged. The averaged digital signals are filtered to remove substantially all radio frequency interference. Absolute signals are then produced by scaling or comparing the filtered signals with a known noise level. The background noise levels are obtained by further averaging the absolute signals. A visual display unit is used to display the background noise levels as a function of frequencies. A frequency surveillance apparatus is also disclosed.

Abstract: An artificial sphincter for closure of a channel in a patient's body communicating with an opening adjacent the outside of the patient's body. The sphincter comprises, an elongated sheet of relatively thin flexible material containing a particulate first material dispersed throughout a substantial portion of the sheet, with the sheet extending at least partially around the channel. The sphincter also has a plug having an elongated annular sleeve of elastic material defining a cavity communicating with a port in the plug, such that the sleeve may be inflated in the body channel. The sleeve has a second particulate material dispersed throughout a region in the sleeve, with at least one of the first and second materials comprising a permanent magnetic material, and with the other of the first and second materials comprising a material substantially susceptible to the one magnetic material.