Systems and methods for determining physiological information using selective transform data
AssigneeNellcor Puritan Bennett Ireland
InventorsBraddon M. Van Slyke, Paul Stanley Addison, James Nicholas Watson, Scott McGonigle
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Abstract
According to embodiments, a pulse band region is identified in a wavelet scalogram of a physiological signal (e.g., a plethysmograph or photoplethysmograph signal). Components of the scalogram at scales larger than the identified pulse band region are then used to determine a baseline signal in wavelet space. The baseline signal may then be used to normalize the physiological signal. Physiological information may be determined from the normalized signal. For example, oxygen saturation may be determined using a ratio of ratios or any other suitable technique.
Claims20
A method for processing a plethysmograph signal comprising:
- using processing circuitry for:
- receiving, from a sensor, the plethysmograph signal,
- transforming the received plethysmograph signal using a continuous wavelet transform,
- computing a scalogram of the plethysmograph signal based at least in part on the transformed signal,
- defining a pulse band region in the scalogram,
- identifying at least some components of the scalogram below the pulse band region,
- computing the inverse continuous wavelet transform of the identified components,
- generating a baseline signal based at least in part on the computed inverse continuous wavelet transform of the identified components and a DC component of the received plethysmograph signal, and
- determining physiological information based at least in part on the baseline signal;
- and
- outputting the physiological information to an output device.
A system for processing a plethysmograph signal, comprising:
- a sensor configured to receive the plethysmograph signal;
- processing circuitry configured to:
- transform the received plethysmograph signal using a continuous wavelet transform,
- compute a scalogram of the plethysmograph signal based at least in part on the transformed signal,
- define a pulse band region in the scalogram,
- identify at least some components of the scalogram below the pulse band region,
- compute the inverse continuous wavelet transform of the identified components,
- generate a baseline signal based at least in part on the computed inverse continuous wavelet transform of the identified components and a DC component of the received plethysmograph signal, and
- determine physiological information based at least in part on the baseline signal;
- and
- an output device to receive the physiological information.
Dependencies are inferred from the claim text.