Patent ID: 11918373
Assignee: RESMED PTY LTD
Field: Medical technology (Instruments)
Classification: CPC A | IPC A

Claim 15:
16. A system for estimating a total sleep time of a patient during a monitoring session, the system comprising a medical screening device including a plurality of sensors, the medical screening device being configured to be mounted on the patient's body during sleep, the system comprising:
an actigraph of the plurality of sensors, configured to generate an actigraphy signal representing acceleration of the actigraph in each of three orthogonal axes; and, one or more processors of the screening device and/or in communication with the screening device, the one or more processors configured to:, receive, from the actigraph, the actigraphy signal;
determine an activity count for each epoch of a plurality of overlapping epochs, from the actigraphy signal, wherein the plurality of overlapping epochs includes at least one overlapping epoch that overlaps a previous epoch and a succeeding epoch;
determine a sleep/wake state of the patient during each epoch of the plurality of overlapping epochs by processing the actigraphy signal; and
compute an estimate of the total sleep time from the sleep/wake state of the patient during each epoch,
wherein the one or more processors are configured to determining the sleep/wake state of the patient during each epoch by:
determining a result of comparing a ratio of the activity count of two overlapping epochs, to a first activity threshold, the ratio of the activity count of two overlapping epochs being a ratio of the activity count for an overlapping epoch to the activity count for a previous epoch that immediately precedes and overlaps with the overlapping epoch, and
determining the sleep/wake state of the patient during the overlapping epoch based at least in part on the result of the comparing.