Abstract: An infusion pump (e.g., an electrokinetic infusion pump) includes an infusion pump module and an engine that can drive a moveable piston non-mechanically. In addition, the infusion pump module includes a position detector configured for sensing a dispensing state of the infusion pump module. Such information can be utilized in a control scheme to control fluid displacement within and out of the pump. Descriptions of different types of position detectors, such as magnetic sensors (e.g., an anisotropic magnetic resistive sensor), and their implementation in detecting infusion pump fluid displacement are described.

Abstract: Detector signals in a pulse oximeter are analyzed to determine a quality of the signals in relation to desired information content or artifact content. The analysis involves performing a transform on a signal to obtain frequency related information and analyzing the frequency related information to obtain a value independent of a shape and waveform of a spectrum of the time-based signal. The analysis involves consideration of the relative phase of the fundamental and harmonic components of a signal. Signals including desired physiological information can be distinguished from artifact affected signals. Based on this analysis, signals can be validated or an appropriate processing algorithm can be selected.

Abstract: Detector signals in a pulse oximeter are analyzed to determine a quality of the signals in relation to desired information content or artifact content. The analysis involves performing a transform on a signal to obtain frequency related information and analyzing the frequency related information to obtain a value independent of a shape and waveform of a spectrum of the time-based signal. In one implementation, the analysis involves the relative amplitude or power measures of corresponding peaks in the red and infrared spectra. For example, the ratio of the amplitude of the fundamental peak in the red spectrum and the amplitude of the fundamental peak in the infrared spectrum may be tracked over time. In another implementation, the analysis involves consideration of the relative phase of the fundamental and harmonic components of a signal. In either case, signals including desired physiological information can be distinguished from artifact affected signals.