Swallowing action measurement device and swallowing action support system
A swallowing action measurement device includes a holder, a sound detector and a posture detector. The holder is fitted to a neck region of a person being measured from behind. The sound detector is held in the holder in contact with the outer side surface of the neck region close to the epiglottis, and detects sound associated with at least a swallowing action of the person being measured and outputs a measured sound signal. The posture detector detects a posture of the person being measured.
1. A swallowing action measurement device comprising:
a holder configured to be fitted to a neck region of a person being measured from behind;
a sound detector mounted in the holder and configured to be in contact with an outer side surface of the neck region close to an epiglottis and configured to detect sound associated with at least a swallowing action of the person being measured and output a measured sound signal;
a posture detector system configured to detect a posture of the person being measured and output a measured posture signal; and
a computing device including an analysis unit configured to discriminate among epiglottis closing sound, food bolus moving sound and epiglottis opening sound from the measured sound signal based upon frequency characteristics and output the epiglottis closing sound, food bolus moving sound and epiglottis opening sound as a series of items of swallowing action information in association with the measured posture signal in real time when each sound is detected,
the computing device including a determination unit configured to compare predetermined temporal characteristics and frequency characteristics of the measured sound signal included in the swallowing action information in real time with predetermined temporal characteristics and frequency characteristics of a standard sound signal preset for the swallowing action, and output a proper signal indicating that the swallowing action is in a proper state while a deviation is within a predetermined range and output an improper signal indicating that the swallowing action is in an improper state when the deviation exceeds the predetermined range;
the computing device including a controller configured to output the swallowing action information as swallowing information unique to the person being measured in association with the proper signal and the improper signal; and
the computing device including a memory configured to store the standard sound signal and the swallowing information,
wherein:
the sound detector includes a single vibration detector or a pair of vibration detectors configured to be disposed along a direction in which a food bolus is moved by the swallowing action;
the analysis unit is configured to calculate a speed of motion of the food bolus based on the measured sound signal detected by the single vibration detector or the pair of vibration detectors and outputs the speed of motion in addition to the swallowing action information;
the controller averages the measured sound signals included in the swallowing information associated with the proper signal, among past unique swallowing information stored in the memory, and replaces the standard sound signal stored in the memory with an averaged signal; and
the predetermined temporal characteristics include a sound duration.
2. The device of claim 1 , wherein:
the sound detector includes the single vibration detector or pair of vibration detectors configured to be disposed plane-symmetrically with regard to a median plane of the person being measured; and
the analysis unit is configured to determine whether the swallowing action is dominant on right or dominant on left, based on a difference between right and left measured sound signals detected by the pair of vibration detectors, and the analysis unit is configured to output a determination result in addition to the swallowing action information.
3. The device of claim 1 , wherein:
the sound detector includes the single vibration detector or pair of vibration detectors configured to be disposed plane-symmetrically with regard to a median plane of the person being measured; and
the analysis unit is configured to determine whether the swallowing action is dominant on right or dominant on left based on a difference between right and left measured sound signals detected by the single vibration detector or pair of vibration detectors and the measured posture signal, and the analysis unit is configured to output a determination result in addition to the swallowing action information.
4. The device of claim 1 , wherein:
the computing device further comprises a control unit located away from the holder and within a range where the control unit is allowed to be operated by the person being measured and equipped with the analysis unit, the determination unit, the controller and the memory;
a first communication circuit built in the holder and configured to transmit a signal including at least the measured sound signal and the measured posture signal; and
a second communication circuit built in the control unit and configured to receive a signal including at least the measured sound signal and the measured posture signal.
5. The device of claim 4 , wherein the first communication circuit and the second communication circuit wirelessly communicate with each other.
6. The device of claim 1 , wherein the analysis unit, the determination unit, the controller and the memory are incorporated into the holder.
7. The device of claim 6 , further comprising a battery mounted on the holder and configured to supply power to the sound detector, the posture detector system, the analysis unit, the determination unit, the controller and the memory.
8. The device of claim 1 , further comprising input elements for starting and terminating measurement for calibration of the sound detector and the posture detector system,
wherein the controller is configured to store the measured sound signal and the measured posture signal, which are detected from start to end of the calibration, in the memory as the standard sound signal and a standard posture signal, respectively.
9. The device of claim 8 , wherein the determination unit is configured to compare the measured posture signal with the standard posture signal, and the determination unit is configured to output the proper signal while a deviation is within a predetermined range and outputs the improper signal when the deviation exceeds the predetermined range.
10. The device of one of claims 8 and 9 , wherein the controller is configured to average the measured posture signals included in the swallowing information associated with the proper signal, among past unique swallowing information stored in the memory, and the controller is configured to store an averaged signal in the memory as the standard posture signal.
11. A swallowing action measurement device comprising:
a holder configured to be fitted to a neck region of a person being measured from behind;
a sound detector mounted in the holder and configured to be in contact with an outer side surface of the neck region close to an epiglottis and configured to detect sound associated with at least a swallowing action of the person being measured and output a measured sound signal;
a posture detector system configured to detect a posture of the person being measured and output a measured posture signal; and
a computing device including an analysis unit configured to discriminate among epiglottis closing sound, food bolus moving sound and epiglottis opening sound from the measured sound signal based upon frequency characteristics and output the epiglottis closing sound, food bolus moving sound and epiglottis opening sound as a series of items of swallowing action information in association with the measured posture signal in real time when each sound is detected,
the computing device including a determination unit configured to compare predetermined temporal characteristics and frequency characteristics of the measured sound signal included in the swallowing action information in real time with predetermined temporal characteristics and frequency characteristics of a standard sound signal preset for the swallowing action, and output a proper signal indicating that the swallowing action is in a proper state while a deviation is within a predetermined range and output an improper signal indicating that the swallowing action is in an improper state when the deviation exceeds the predetermined range;
the computing device including a controller configured to output the swallowing action information as swallowing information unique to the person being measured in association with the proper signal and the improper signal; and
the computing device including a memory configured to store the standard sound signal and the swallowing information,
wherein:
the posture detector system includes a plurality of posture detectors configured to be disposed along a direction in which a food bolus is moved by the swallowing action and each configured to output the measured posture signal; and
the analysis unit is configured to calculate a turn, a bending direction and a bending angle of the neck region based on the measured posture signal output from each of the plurality of posture detectors and outputs the turn, bending direction and bending angle in addition to the swallowing action information.
12. The device of one of claims 1 and 11 , wherein the posture detector system is attached to the holder, the holder is configured to be located on a median plane of the person being measured, wherein the posture detector system includes an electronic compass configured to detect magnetic intensity of earth's magnetism for three orthogonal axes, and configured to output a measured posture signal including the magnetic intensity.
13. The device of claim 12 , wherein the posture detector system is configured to detect acceleration in a direction along the three orthogonal axes and angular velocity with each of the three orthogonal axes as a center axis and outputs the acceleration and the angular velocity with the acceleration and the angular velocity included in the measured posture signal.
14. The device of claim 12 , wherein the sound detector includes a pair of vibration detectors configured to be disposed plane-symmetrically with regard to the median plane.
15. The device of claim 11 , wherein:
the controller averages the measured sound signals included in the swallowing information associated with the proper signal, among past unique swallowing information stored in the memory, and replaces the standard sound signal stored in the memory with an averaged signal, and
the predetermined temporal characteristics include a parameter that varies with a fluidity of a food bolus.
16. A swallowing action support system comprising:
a holder configured to be fitted to a neck region of a person being measured from behind, wherein the holder is configured to be located on a median plane of the person being measured;
a sound detector mounted in the holder and configured to be in contact with an outer side surface of the neck region close to an epiglottis and configured to detect sound associated with at least a swallowing action of the person being measured and output a measured sound signal;
a posture detector system attached to the holder, the holder configured to be located on a median plane of the person being measured, the posture detector system including an electronic compass to detect magnetic intensity of earth's magnetism for three orthogonal axes, and configured to output a measured posture signal including the magnetic intensity;
a computing device including an analysis unit configured to discriminate among epiglottis closing sound, food bolus moving sound and epiglottis opening sound from the measured sound signal based upon frequency characteristics and output the epiglottis closing sound, food bolus moving sound and epiglottis opening sound as a series of items of swallowing action information in association with the measured posture signal in real time when each sound is detected;
the computing device including a determination unit configured to compare predetermined temporal characteristics and frequency characteristics of the measured sound signal included in the swallowing action information in real time with predetermined temporal characteristics and frequency characteristics of a standard sound signal preset for the swallowing action, and the determination unit is configured to output a proper signal indicating that the swallowing action is in a proper state while a deviation is within a predetermined range and output an improper signal indicating that the swallowing action is in an improper state when the deviation exceeds the predetermined range;
the computing device including a controller configured to output the swallowing action information as swallowing information unique to the person being measured in association with the proper signal and the improper signal and output a first command signal corresponding to the proper signal and a second command signal corresponding to the improper signal;
a notification circuit including a notification unit configured to make a first notification in response to the first command signal and make a second notification different from the first notification, in response to the second command signal; and
the computing device including a memory configured to store the standard sound signal and unique swallowing information,
wherein:
the sound detector includes a pair of vibration detectors configured to be disposed along a direction in which a food bolus is moved by the swallowing action;
the posture detector system includes a plurality of posture detectors configured to be disposed along a direction in which a food bolus is moved by the swallowing action and each configured to output the measured posture signal;
the analysis unit is configured to calculate a speed of motion of the food bolus based on the measured sound signal detected by the pair of vibration detectors and outputs the speed of motion in addition to the swallowing action information, and calculates a turn, a bending direction and a bending angle of the neck region based on the measured posture signal output from each of the plurality of posture detectors and outputs the turn, bending direction and bending angle in addition to the swallowing action information;
the controller averages the measured sound signals included in the swallowing information associated with the proper signal, among past unique swallowing information stored in the memory, and replaces the standard sound signal stored in the memory with an averaged signal,
the predetermined temporal characteristics include a sound duration.
17. The system of claim 16 , wherein the posture detector system is configured to detect acceleration in a direction along the three orthogonal axes and angular velocity with each of the three orthogonal axes as a center axis and outputs the acceleration and the angular velocity with the acceleration and the angular velocity included in the measured posture signal.
18. The system of one of claims 16 and 17 , further comprising:
an external unit located away from the holder and within a range where the external unit is allowed to be perceived by the person being measured;
a first communication circuit configured to transmit the first command signal and the second command signal wirelessly; and
a second communication circuit built in the external unit and configured to receive the first command signal and the second command signal wirelessly,
wherein the notification unit includes an external light source disposed in at least the external unit and is configured to cause the external light source to emit light in a first light emission pattern as the first notification when the notification unit detects the first command signal and cause the external light source to emit light in a second light emission pattern other than the first light emission pattern, as the second notification when the notification unit detects the second command signal.
19. The system of claim 18 , comprising a control unit located away from the holder and within a range where the control unit is allowed to be operated by the person being measured and equipped with the analysis unit, the determination unit, the controller, the memory and the first communication circuit.
20. The system of claim 18 , wherein the holder is equipped with the analysis unit, the determination unit, the controller, the memory and the first communication circuit.
21. The system of claim 18 , wherein:
the first communication circuit is connectable to a network to which a database and a management terminal are connected; and
the controller is configured to store the swallowing information in the database together with identification information of the person being measured.
22. The system of claim 21 , further comprising input elements operated for calibration of the sound detector and the posture detector,
wherein when the input elements are operated, the controller averages the measured sound signals and the measured posture signals included in the unique swallowing information associated with the proper signal based on the identification information and stores averaged signals in the memory as the standard sound signal and a standard posture signal, respectively.
23. The system of claim 16 , wherein the notification unit includes a pair of holder light sources disposed in the holder configured to be plane plane-symmetric with regard to the median plane and the notification unit is configured to cause the holder light sources to emit light in a first light emission pattern as the first notification when the notification unit detects the first command signal and cause the holder light sources to emit light in a second light emission pattern other than the first light emission pattern, as the second notification when the notification unit detects the second command signal.