Pulse oximeter

A pulse oximeter comprising:

• a red light sensor configured to irradiate a subject with red light and detect the red light transmitted through or reflected from the subject;
• an infrared light sensor configured to irradiate the subject with infrared light and detect the infrared light transmitted through or reflected from the subject;
• a control device configured to process detection signals from the red light sensor and the infrared light sensor;
• and
• a display unit configured to display information obtained by the control device, wherein
• the control device
• generates, based on the detection signals from the red light sensor and the infrared light sensor, an oxygen saturation data group indicating an oxygen saturation of the subject,
• calculates an indicator value based on at least one of a red light signal intensity ratio indicating a ratio of an amplitude of a vibration component in the detection signal output by the red light sensor to a signal intensity of the detection signal and an infrared light signal intensity ratio indicating a ratio of an amplitude of a vibration component in the detection signal output by the infrared light sensor to a signal intensity of the detection signal, and
• displays, on the display unit, a graph in which the oxygen saturation data group and the indicator value are displayed on the same time axis.

A pulse oximeter comprising:

• a red light sensor configured to irradiate a subject with red light and detect the red light transmitted through or reflected from the subject;
• an infrared light sensor configured to irradiate the subject with infrared light and detect the infrared light transmitted through or reflected from the subject;
• a control device configured to process detection signals from the red light sensor and the infrared light sensor;
• and
• a display unit configured to display information obtained by the control device, wherein
• the control device
• calculates an oxygen saturation of the subject based on the detection signals from the red light sensor and the infrared light sensor,
• calculates, as an indicator value, an analysis result of time variation analysis on at least one of a red light signal intensity ratio indicating a ratio of an amplitude of a vibration component in the detection signal output by the red light sensor to a signal intensity of the detection signal and an infrared light signal intensity ratio indicating a ratio of an amplitude of a vibration component in the detection signal output by the infrared light sensor to a signal intensity of the detection signal, and
• displays the oxygen saturation and the analysis result on the display unit, and displays the oxygen saturation or the analysis result in different display formats when the analysis result is equal to or more than a predetermined threshold or when the analysis result is less than the threshold.