Antenna device for biological measurement, pulse wave measuring device, blood pressure measuring device, apparatus, biological information measuring method, pulse wave measuring method, and blood pressure measuring method

An antenna device for biological measurement that measures biological information, the device comprising:

• a belt worn as surrounding a measurement target site of a living body;
• a transmission/reception antenna group provided to the belt and including a plurality of antenna elements arranged, in an area where the belt is spread in a strip-like manner, being spaced apart from each other in one direction or two orthogonal directions;
• a transmission circuit configured to emit a radio wave toward the measurement target site using any one of antenna elements included in the transmission/reception antenna group as a transmission antenna, in a wearing state where the belt is worn as surrounding an outer surface of the measurement target site;
• a reception circuit configured to receive a radio wave reflected from the measurement target site using any one of antenna element included in the transmission/reception antenna group as a reception antenna;
• an antenna control unit configured to select or to weight by switching a transmission/reception antenna pair formed of the transmission antenna and the reception antenna among the plurality of antenna elements based on an output of the reception circuit;
• and
• a storage unit configured to store a signal-to-noise ratio of received signal corresponding to selection or weighting every time the antenna control unit switches the selection or weighting once,
• wherein the antenna control unit determines a next selection or weighting based on a signal-to-noise ratio corresponding to past selection or weighting, which is stored in the storage unit, and a signal-to-noise ratio corresponding to the current selection or weighting.

A biological information measuring method that measures biological information using a belt to which a transmission/reception antenna group is provided, wherein

• the transmission/reception antenna group includes a plurality of antenna elements arranged spaced apart from each other in a longitudinal direction and/or a width direction of the belt,
• the biological information measuring method comprising:
• wearing the belt as surrounding an outer surface of a measurement target site of the living body into a wearing state so that the transmission/reception antenna group is placed corresponding to an artery passing through the measurement target site;
• and
• in the wearing state, while emitting, by a transmission circuit, a radio wave toward the measurement target site using any one of antenna elements included in the transmission/reception antenna group as a transmission antenna and receiving, by a reception circuit, a radio wave reflected by the the measurement target site using any one of antenna elements included in the transmission/reception antenna group as a reception antenna, weighting the transmission/reception antenna pair formed of the transmission antenna and the reception antenna among the plurality of antenna elements based on an output from the reception circuit.

A pulse wave measuring method that measures a pulse wave of a measurement target site of a living body using a belt to which a transmission/reception antenna group is provided, wherein

• the transmission/reception antenna group includes a plurality of antenna elements arranged spaced apart from each other in a longitudinal direction and/or a width direction of the belt,
• the pulse wave measuring method comprising:
• wearing the belt as surrounding an outer surface of a measurement target site into a wearing state so that the transmission/reception antenna group is placed corresponding to an artery passing through the measurement target site;
• in the wearing state, while emitting, by a transmission circuit, a radio wave toward the measurement target site using any one of antenna elements included in the transmission/reception antenna group as a transmission antenna and receiving, by a reception circuit, a radio wave reflected by the the measurement target site using any one of antenna elements included in the transmission/reception antenna group as a reception antenna, weighting the transmission/reception antenna pair formed of the transmission antenna and the reception antenna among the plurality of antenna elements based on an output from the reception circuit;
• and
• acquiring a pulse wave signal indicating a pulse wave at the artery passing through the measurement target site based on the output from the reception circuit received via the weighted transmission/reception antenna pair.

A blood pressure measuring method that measures blood pressure at a measurement target site of a living body using a belt to which two sets of transmission/reception antenna groups are integrally provided, wherein

• the two sets of the transmission/reception antenna groups are arranged spaced apart from each other in a width direction of the belt and respectively include a plurality of antenna elements arranged spaced apart from each other in a longitudinal direction and/or the width direction of the belt,
• the blood pressure measuring method comprising:
• wearing the belt as surrounding an outer surface of the measurement target site into a wearing state so that a first set of transmission/reception antenna group of the two sets is placed corresponding to an upstream portion of an artery passing through the measurement target site and a second set of transmission/reception antenna group is placed corresponding to a downstream portion of the artery;
• in the wearing state, respectively in the two sets, while emitting, by a transmission circuit, a radio wave toward the measurement target site using any one of antenna elements included in the transmission/reception antenna group as a transmission antenna and receiving, by a reception circuit, a radio wave reflected by the measurement target site using any one of antenna elements included in the transmission/reception antenna group as a reception antenna, weighting a transmission/reception antenna pair formed of the transmission antenna and the reception antenna among the plurality of antenna elements based on an output from the reception circuit;
• respectively in the two sets, acquiring a pulse wave signal indicating a pulse wave at the artery passing through the measurement target site based on the output from the reception circuit received via the weighted transmission/reception antenna pair;
• acquiring a time difference between the pulse wave signals respectively received in the two sets as a pulse wave transit time;
• and
• calculating a blood pressure value based on the acquired pulse wave transit time using a predetermined correspondence equation between the pulse wave transit time and the blood pressure.

A biological information measuring method that measures biological information using a belt to which a transmission/reception antenna group is provided, wherein

• the transmission/reception antenna group includes a plurality of antenna elements arranged spaced apart from each other in a longitudinal direction and/or a width direction of the belt,
• the biological information measuring method comprising:
• wearing the belt as surrounding an outer surface of a measurement target site of a living body into a wearing state so that the transmission/reception antenna group is placed corresponding to an artery passing through the measurement target site;
• in the wearing state, while emitting, by a transmission circuit, a radio wave toward the measurement target site using any one of antenna elements included in the transmission/reception antenna group as a transmission antenna and receiving, by a reception circuit, a radio wave reflected by the measurement target site using any one of antenna elements included in the transmission/reception antenna group as a reception antenna, selecting by switching, or weighting a transmission/reception antenna pair formed of the transmission antenna and the reception antenna among the plurality of antenna elements based on an output from the reception circuit,
• storing a signal-to-noise ratio of received signal corresponding to selection or weighting in a storage unit every time the selection or weighting is switched once, and
• determining a next selection or weighting based on a signal-to-noise ratio corresponding to past selection or weighting stored in the storage unit and a signal-to-noise ratio corresponding to current selection or weighting.

A pulse wave measuring method that measures a pulse wave at a measurement target site of a living body using a belt to which a transmission/reception antenna group is provided, wherein

• the transmission/reception antenna group includes a plurality of antenna elements arranged spaced apart from each other in a longitudinal direction and/or a width direction of the belt,
• the pulse wave measuring method comprising:
• wearing the belt as surrounding an outer surface of the measurement target site into a wearing state so that the transmission/reception antenna group is placed corresponding to an artery passing through the measurement target site;
• in the wearing state, while emitting, by a transmission circuit, a radio wave toward the measurement target site using any one of antenna elements included in the transmission/reception antenna group as a transmission antenna and receiving, by a reception circuit, a radio wave reflected by the measurement target site using any one of antenna elements included in the transmission/reception antenna group as a reception antenna, selecting by switching, or weighting a transmission/reception antenna pair formed of the transmission antenna and the reception antenna among the plurality of antenna elements based on an output from the reception circuit;
• storing a signal-to-noise ratio of received signal corresponding to selection or weighting in a storage unit every time the selection or weighting is switched once;
• determing a next selection or weighting based on a signal-to-noise ratio corresponding to past selection or weighting stored in the storage unit and a signal-to-noise ratio corresponding to current selection or weighting;
• and
• acquiring a pulse wave signal indicating a pulse wave at the artery passing through the measurement target site based on the output from the reception circuit received via the selected or weighted transmission/reception antenna pair.

A blood pressure measuring method that measures blood pressure at a measurement target site of a living body using a belt to which two sets of transmission/reception antenna groups are integrally provided, wherein

• the two sets of the transmission/reception antenna group are arranged spaced apart from each other in a width direction of the belt and respectively include a plurality of antenna elements arranged spaced apart from each other in a longitudinal direction and/or the width direction of the belt,
• the blood pressure measuring method comprising:
• wearing the belt as surrounding an outer surface of the measurement target site into a wearing state so that a first set of the transmission/reception antenna group of the two sets is placed corresponding to an upstream portion of an artery passing through the measurement target site and a second set of the transmission/reception antenna group is placed corresponding to a downstream portion of the artery;
• in the wearing state, respectively in the two sets, while emitting, by a transmission circuit, a radio wave toward the measurement target site using any one of antenna elements included in the transmission/reception antenna group as a transmission antenna and receiving, by a reception circuit, a radio wave reflected by the measurement target site using any one of antenna elements included in the transmission/reception antenna group as a reception antenna, selecting by switching, or weighting a transmission/reception antenna pair formed of the transmission antenna and the reception antenna among the plurality of antenna elements based on an output from the reception circuit;
• storing a signal-to-noise ratio of received signal corresponding to selection or weighting in a storage unit every time the selection or weighting is switched once;
• determing a next selection or weighting based on a signal-to-noise ratio corresponding to past selection or weighting stored in the storage unit and a signal-to-noise ratio corresponding to current selection or weighting;
• respectively in the two sets, acquiring a pulse wave signal indicating a pulse wave at the artery passing through the measurement target site based on the output from the reception circuit received via the selected or weighted transmission/reception antenna pair;
• acquiring a time difference between the pulse wave signals respectively acquired in the two sets as a pulse wave transit time;
• and
• calculating a blood pressure value based on the acquired pulse wave transit time using a predetermined correspondence equation between the pulse wave transit time and the blood pressure.