Abstract: A sensor comprising: including a first light detector and a second light detector configured to concurrently detect light, and an optical blocking filter. The first light detector is configured to detect light that enters the sensor to produce a first detected signal, the optical blocking filter is configured to filter the light that enters the sensor to produce filtered light, and the second light detector is configured to detect the filtered light to produce a second detected signal. There is also a subtraction element configured to subtract the second detected signal from the first detected signal to produce a subtracted signal, wherein the subtracted signal is a sensor signal usable for producing a physiological measurement result.

Abstract: A system and method for measuring absolute pressure applied to a piezoelectric element by measuring a transition time of a voltage pulse applied to a piezoelectric element. The transition time (such as the rise time and/or fall time of the voltage pulse) is affected by the capacitance of the piezoelectric element, which in turn is affected by the amount of pressure currently being applied to the piezoelectric element. The system may also provide haptic feedback via the same piezoelectric element.

Abstract: A system and method for measuring absolute pressure applied to a piezoelectric element by measuring a transition time of a voltage pulse applied to a piezoelectric element. The transition time (such as the rise time and/or fall time of the voltage pulse) is affected by the capacitance of the piezoelectric element, which in turn is affected by the amount of pressure currently being applied to the piezoelectric element. The system may also provide haptic feedback via the same piezoelectric element.

Abstract: A system and method for accurately determining the positioning of a lens system. The lens system includes a lens and a variable light reflecting surface. A position sensor includes a light source and a light detector. An initial signal is sent from the light source to the variable light reflecting surface. The light reflecting surface reflects the initial signal to the light detector at a reflection region. The intensity of the reflected signal is dependent upon the location of the reflection region. An electrical output signal is generated based upon the reflected signal from the light source, with the electrical output signal providing positioning information for the lens system.