Abstract: A spectrometer system includes a thermal light source for illuminating a sample, where the thermal light source includes a filament that emits light when heated. The system additionally includes a spectrograph for measuring a light spectrum from the sample and an electrical circuit for supplying electrical current to the filament to heat the filament and for controlling a resistance of the filament. The electrical circuit includes a power supply that supplies current to the filament, first electrical components that sense a current through the filament, second electrical components that sense a voltage drop across the filament, third electrical components that compare a ratio of the sensed voltage drop and the sensed current with a predetermined value, and fourth electrical components that control the current through the filament or the voltage drop across the filament to cause the ratio to equal substantially the predetermined value.

Abstract: The apparatus and methods of the present invention provide a non-invasive measurement of blood pressure with a frequency that approximates a continuous measurement. Blood pressure measurement provides information that is both clinically and diagnostically significant. In accordance with an aspect of the present invention, a method for providing a non-invasive measurement of blood pressure, includes obtaining a first input signal and a second input signal indicative of occlusive measurements of systolic blood pressure and diastolic blood pressure, respectively; tracking a signal indicative of pulse pressure; continuously measuring a third signal indicative of mean blood pressure; and processing the signals to obtain a measurement indicative of systolic and diastolic blood pressure, wherein at least a portion of the measurement indicative of systolic and diastolic blood pressure is continuous.