Pulse measurement device, biological information estimation device, pulse measurement method, and recording medium
A pulse measurement device including a plurality of light emitters which are disposed on a measurement surface of a substrate to be attached to the skin of a subject to be subjected to pulse measurement and emit light toward the skin of the subject, a light receiver which is disposed on the measurement surface of the substrate and comprises a plurality of light reception units that receive reflected light of the light emitted from the light emitters, and a control unit which causes the light emitters to emit light, receives, reception signals corresponding to the reflected light received by the light receiver from the light receiver, optimizes the intensity of the reception signals using a normalization constant set for the respective light emitters, and outputs the reception signals having intensities optimized using the normalization constants as a pulse signals.
1 . A pulse measurement device comprising:
a plurality of light emitters that is disposed on a measurement face of a substrate to be attached to a skin of a subject to be subjected to pulse measurement and emits light toward the skin of the subject;
at least one light receiver that is disposed on the measurement face of the substrate and includes a plurality of light receiving parts that receives reflected light of the light emitted from the plurality of light emitters; and
a controller comprising
a first memory storing instructions; and
a first processor connected to the first memory and configured to execute the instructions to
cause the plurality of light emitters to emit the light,
receive, from the at least one light receiver, a reception signal related to the reflected light of the light received by each of the at least one light receivers,
optimize intensity of the reception signal using a normalization constant determined during a calibration period by emitting modulated light modulated at a specific frequency from each of the plurality of light emitters, calculating a degree of influence of each of the plurality of light emitters on each of the plurality of light receiving parts according to received light intensity of reflected light of the modulated light,
set the normalization constant by which the intensity of the reception signal is uniform in each of the plurality of light receiving parts, the normalization constant being individually set for each of the plurality of light emitters for each of the plurality of light receiving parts, and
output the reception signal having the intensity optimized using the normalization constants as a pulse signal.
2 . The pulse measurement device according to claim 1 , wherein
the first processor is further configured to execute the instructions to
optimize an optical output of each of the plurality of light emitters according to the normalization constant set for each of the plurality of light emitters.
3 . The pulse measurement device according to claim 1 , wherein
the first processor is further configured to execute the instructions to, during a pulse measurement period,
emit an optical signal from each of the plurality of light emitters, and
optimize the intensity of the reception signal by multiplying the reception signal related to the reflected light of the optical signal of each of the plurality of light emitters, the reception signal being acquired from each of the plurality of light receiving parts, by the normalization constant of each of the plurality of light emitters, the normalization constant being set in each of the plurality of light receiving parts.
4 . The pulse measurement device according to claim 1 , wherein
the light receiver includes a light receiving element array in which the plurality of light receiving parts is disposed in a two-dimensional array.
5 . The pulse measurement device according to claim 4 , wherein
the first processor is further configured to execute the instructions to;
cause the plurality of light emitters to emit detection light for detecting a position of a blood vessel included in a measurable range of the light receiving element array,
set a range to be measured in the measurable range based on the reception signal related to the reflected light of the detection light received by the light receiving element array, and
set the normalization constant for each of the plurality of light receiving parts in a range related to the set range to be measured.
6 . A biological information estimation device comprising:
the pulse measurement device according to claim 1 ; and
an estimation device comprising:
a second memory storing instructions; and
a second processor connected to the second memory and configured to execute the instructions to:
acquire a pulse signal of a subject measured by the pulse measurement device, and
estimate biological information of the subject based on the acquired pulse signal.
7 . The biological information estimation device according to claim 6 , wherein
the second processor is further configured to execute the instructions to:
estimate a pulse rate of the subject using the pulse signal of the subject, and
output information related to the estimated pulse rate.
8 . The biological information estimation device according to claim 6 , wherein
the second processor is further configured to execute the instructions to;
estimate an emotion state of the subject using the pulse signal of the subject, and
output information according to the estimated emotion state.
9 . The biological information estimation device according to claim 8 , wherein
the second processor is further configured to execute the instructions to;
estimate the emotion state of the subject by using a machine training method, and wherein
the information according to the estimated emotion state is for providing recommended information to enable a decision making by the subject to bring the emotion state of the subject closer to a normal state.
10 . A pulse measurement method using a plurality of light emitters that emits light toward a skin of a subject to be subjected to pulse measurement and at least one light receiver including a plurality of light receiving parts that receives reflected light of the light emitted from the plurality of light emitters, the pulse measurement method causing controller to execute:
causing the plurality of light emitters to emit the light;
receiving, from the at least one light receiver, a reception signal related to the reflected light of the light received by each of the at least one light receivers;
optimizing intensity of the reception signal using a normalization constant determined during a calibration period by emitting modulated light modulated at a specific frequency from each of the plurality of light emitters, calculating a degree of influence of each of the plurality of light emitters on each of the plurality of light receiving parts according to received light intensity of reflected light of the modulated light;
setting the normalization constant by which the intensity of the reception signal is uniform in each of the plurality of light receiving parts, the normalization constant being individually set for each of the plurality of light emitters for each of the plurality of light receiving parts; and
outputting the reception signal having the intensity optimized using the normalization constants as a pulse signal.
11 . A non-transitory recording medium storing a program for controlling a plurality of light emitters that emits light toward a skin of a subject to be subjected to pulse measurement and at least one light receiver including a plurality of light receiving parts that receives reflected light of the light emitted from the plurality of light emitters, the program causing a computer to execute the steps of:
causing the plurality of light emitters to emit the light;
receiving, from the at least one light receiver, a reception signal related to the reflected light of the light received by each of the at least one light receivers;
optimizing intensity of the reception signal using a normalization constant determined during a calibration period by emitting modulated light modulated at a specific frequency from each of the plurality of light emitters, calculating a degree of influence of each of the plurality of light emitters on each of the plurality of light receiving parts according to received light intensity of reflected light of the modulated light;
setting the normalization constant by which the intensity of the reception signal is uniform in each of the plurality of light receiving parts, the normalization constant being individually set for each of the plurality of light emitters for each of the plurality of light receiving parts; and
outputting the reception signal having the intensity optimized using the normalization constants as a pulse signal.