Patent ID: 8571619

Claim:
A patient monitoring system comprising: a noninvasive sensor for emitting energy into a patient measurement site and detecting the energy attenuated by the patient measurement site; a processing board comprising: an instrument manager including a memory buffer; and a FFT module in communication with the instrument manager; wherein the instrument manager is adapted to determine a first plurality of total hemoglobin readings over a first time period and to determine a second plurality of total hemoglobin readings over a second time period using the attenuated energy detected by the sensor and to store the first and second plurality of total hemoglobin readings in the memory buffer; wherein the FFT module is adapted to perform a Fourier transform on the first and second plurality of total hemoglobin readings stored in the memory buffer and to determine a variation between of the outputs of the Fourier transform of the first and second total hemoglobin readings; and wherein the instrument manager is adapted to trigger an alarm if the variation reaches a certain threshold.