In this paper, current practice in implementation of pulse oximetry is covered. It is proposed here that the market is divided into three separate segments, each with their own set of unique and overlapping requirements. These requirements are discussed as they relate to each market segment and the unique problems of each are explored. Solutions are suggested for each of the challenges presented. The potential contributions from two suppliers, Freescale and National Semiconductor are presented and discussed. The new Kenetis processors from Freescale are presented as a possible new alternative to the existing family of processors in current use. These need to be supplemented with higher accuracy ADCs & DACs in the more demanding applications of pulse oximetry.