Heart rate information acquisition system, and bed system
A heartbeat information acquisition system configured to acquire heartbeat information of a subject on a bed, including a plurality of load detectors configured to detect a load of the subject on the bed, a waveform acquisition unit configured to acquire, based on outputs of the plurality of load detectors, a plurality of heartbeat waveforms respectively corresponding to the plurality of load detectors, a waveform selection unit configured to select, from the plurality of heartbeat waveforms, a largest amplitude waveform being a heartbeat waveform having a largest amplitude among the plurality of heartbeat waveforms, and a heartbeat information acquisition unit configured to acquire the heartbeat information of the subject based on an output of a load detector, among the plurality of load detectors, corresponding to the largest amplitude waveform.
1 . A heartbeat information acquisition system configured to acquire heartbeat information of a subject on a bed, the heartbeat information acquisition system comprising:
a plurality of load detectors configured to detect a load of the subject on the bed; and
a controller configured to:
acquire, based on outputs of the plurality of load detectors, a plurality of heartbeat waveforms respectively corresponding to the plurality of load detectors;
obtain an integrated value of amplitude in a predetermined period for each of the plurality of heartbeat waveforms;
select, from the plurality of heartbeat waveforms, a waveform having a largest integrated value among the plurality of heartbeat waveforms; and
acquire the heartbeat information of the subject based on an output of a load detector, among the plurality of load detectors, corresponding to the waveform having the largest integrated value.
2 . The heartbeat information acquisition system according to claim 1 , wherein the integrated value is an integrated value of moving average values of each of the plurality of heartbeat waveforms.
3 . The heartbeat information acquisition system according to claim 1 , wherein the controller is configured to use only a positive value of the amplitude of each of the plurality of heartbeat waveforms to calculate the integrated value of the amplitude of each of the plurality of heartbeat waveforms.
4 . The heartbeat information acquisition system according to claim 1 , wherein the controller is further configured to determine whether body movement of the subject is occurring based on an output of at least one of the plurality of load detectors.
5 . The heartbeat information acquisition system according to claim 4 , wherein the controller is configured not to select the waveform having the largest integrated value in a period in which the controller determines that the body movement of the subject is occurring.
6 . The heartbeat information acquisition system according to claim 4 , wherein when the controller determines that the body movement of the subject is occurring, the controller is configured to reselect the waveform having the largest integrated value after the body movement has stopped.
7 . The heartbeat information acquisition system according to claim 1 , wherein the controller is configured to select the waveform having the largest integrated value in a predetermined period.
8 . The heartbeat information acquisition system according to claim 1 , wherein the controller is configured to calculate a heart rate of the subject based on autocorrelation of the waveform having the largest integrated value.
9 . The heartbeat information acquisition system according to claim 1 , wherein the controller is configured to perform peak detection on the waveform having the largest integrated value, and calculate a heart rate of the subject based on a detected peak.
10 . The heartbeat information acquisition system according to claim 1 , wherein the controller is configured to calculate a heart rate of the subject based on frequency analysis of an output of the load detector corresponding to the waveform having the largest integrated value.
11 . A bed system comprising:
a bed; and
the heartbeat information acquisition system according to claim 1 .