Patent ID: 11864885
Assignee: NATIONAL UNIVERSITY CORPORATION CHIBA UNIVERSITY
Field: Medical technology (Instruments)
Classification: CPC A | IPC A

Claim 7:
8. A biological state monitoring system for monitoring a biological state of a subject on a bed over a predetermined monitoring period, the system comprising:
a plurality of load detectors each configured to detect, over time, a load value of the subject on the bed; and
a controller configured to:
obtain a center of gravity position of the subject based on the load value detected by each of the plurality of load detectors;
obtain a respiratory waveform of the subject based on a temporal variation of the center of gravity position of the subject;
successively obtain and output estimated values of a respiratory rate of the subject, based on the respiratory waveform of the subject; and
determine whether or not the subject has a body motion based on dividing a standard deviation of a temporal variation of the load value detected by at least one of the plurality of load detectors by an amplitude of the respiratory waveform,

wherein the monitoring period includes a body motion period in which the subject has the body motion, and a resting period in which the subject merely performs a respiration,
wherein, in a case that the monitoring period shifts from a first resting period to the body motion period and then from the body motion period to a second resting period, the controller is configured to output, in the body motion period and a period after shifting from the body motion period to the second resting period, a last estimated value of the respiratory rate of the subject which is the latest among the estimated values of the respiratory rate of the subject obtained successively in the first resting period, and
wherein the controller is configured to:
obtain an inter-peak distance between two peaks of the respiratory waveform of the subject, the two peaks being firstly and secondly exhibited peaks of the respiratory waveform in the second resting period;
obtain the estimated value of the respiratory rate of the subject by using the equation of R=60/t, provided that t is the inter-peak distance, in seconds, and R is the estimated value of the respiratory rate in one minute of the subject; and

output the obtained estimated value instead of the last estimated value which is the latest among the estimated values obtained successively in the first resting period.