Abstract: An apparatus for measuring the concentration of blood constituents in which the architecture of the electronic processor reduces the amount of controller processing time required for tasks such as data acquisition and generation of system control signals. A demodulator is coupled to a probe for converting a first electrical signal to digital data. An interface is coupled to the demodulator for receiving the digital data and generating interrupts when a first amount of the digital data has been received. A buffer memory is coupled to the interface for storing the digital data. A controller having a controller memory (in specific embodiments, a CPU having a CPU memory) is also coupled to the buffer memory. The controller transfers the digital data from the buffer memory to the controller memory in response to the interrupts. The controller then processes the digital data to calculate the blood oxygen concentration.

Abstract: An apparatus and method for sensing respiratory motion to detect sleep apnea and the like. An acoustic pulse stimulator or generator located on one side of a body sends impulses through the body to impinge on one or more sensors on the opposite side of the body. Because time delay between transmitter and receiver is determined by distance, and because distance is directly related to breathing motions of the body, measurement of the time delay will have a direct correspondence to breathing motions.

Abstract: An electronic processor for calculating in vivo blood oxygenation concentration levels using pulsed light that eliminates both requirements for comparing photosensor signal amplitudes with analog/digital circuit dynamic ranges and also adjusting electronic processor parameters. The invention uses monolithic a/d converters with expanded capacity and a microcontroller/processor with a pulse control module to synchronize switching in an oversampling demodulator with pulsing of light sources to overcome prior circuitry limitations that consumed substantial central processor capacity.