Abstract: An energy-efficient photoreceptor apparatus and a transimpedance amplifier apparatus having high energy-efficiency and low power consumption of which are achieved through multiple distributed gain amplification stages, adaptive loop gain control circuitry and unilateralization, thereby enabling fast and precise performance over a wide range of input-current levels. The high-energy efficiency, robust feedback stability and performance of the present invention can be utilized to achieve sub-milliwatt pulse oximeters and may be employed in other current-to-voltage amplification and conversion applications. The use of analog processing on the outputs of the photoreceptor apparatus also helps lower the overall power of pulse oximeters.

Abstract: The present invention relates to new and useful nucleoside thiophosphoroamidites and polynucleotide phosphorodithioate compounds as well as the processes whereby these compounds may be used for synthesizing new mononucleotides and polynucleotides having phosphorothioate and phosphorodithioate internucleotide linkages.