Abstract: Various methods, devices, and systems are described for aerosolizing a liquid. Embodiments may include sealing the liquid within a reservoir. An output waveform signal may be generated. A nebulizer element may be vibrated to aerosolize the liquid. A negative pressure may be produced within the reservoir as the liquid is aerosolized. The output waveform signal may cause the nebulizer element to vibrate. Embodiments may involve determining a phase shift between a current of the output waveform signal and a voltage of the output waveform signal. Also, embodiments may involve adjusting a frequency of the output waveform signal at least partially based on the phase shift. Further, embodiments may involve adjusting the voltage of the output waveform signal at least partially based on the frequency of the output waveform signal.

Abstract: A device for determining the composition of a mixture of fluids by spectral absorption, comprises: a radiation source; a detector for detecting radiation that has been attenuated by the mixture; and a device for separating the radiation into a wavelength band corresponding to an absorption band of one of the fluids, a wavelength band corresponding to an absorption band of another of the fluids, and at least one reference wavelength band substantially adjacent to each of the absorption bands, and especially adjacent to each side of the absorption band or group of absorption bands. The device may be used to determine the composition of mixtures of oil, water and gaseous hydrocarbons in oil wells where there is a very large degree of time varying scattering e.g. Rayleigh and Mie scattering due to turbulence.

Abstract: A method of non-invasively measuring venous oxygen saturation, comprising: applying a pressure transducer at a first site on a body, applying a drive signal to the external pressure transducer at a predetermined frequency, to cause a series of pulsations of a predetermined magnitude in the venous blood volume in the vicinity of said first site, applying an oximeter device at a second site on the body, measuring output signals received from said oximeter device, said output signals containing a component representative of the modulation of venous blood volume due to said pulsations, deriving a measure of venous oxygen saturation from the frequency response of said output signals.