JP2022022949A - Monitor, method for monitoring, and monitoring program - Google Patents

Abstract

To provide a monitor that can identify an individual by a simple structure.SOLUTION: A monitor 1 includes: a millimeter wave sensor 2 for irradiating an individual with a millimeter wave; and an identification unit 323 for identifying the individual on the basis of a result of measurement by the millimeter wave sensor 2. The identification unit 323 identifies the individual on the basis of the amplitude of a site which regularly vibrates in information on the position and the rate of the individual. The site which regularly vibrates is an artery and a pleural and the vibration is unique to each individual. Since the impedances of an artery and a pleural are largely different from those of other tissues, an artery and a pleural reflect a millimeter wave more easily.SELECTED DRAWING: Figure 2

Description

The present invention relates to a monitoring device using a millimeter wave sensor.

Millimeter waves with a frequency of 30 GHz to 300 GHz and a wavelength of 1 mm to 1 cm are in the frequency band close to light in radio waves, have very strong straightness, and have excellent environmental resistance (rain, fog, snow, dirt). It has the features of being able to be miniaturized and having a large information transmission capacity. Millimeter-wave sensors are used, for example, in automobile collision prevention systems because they can instantly detect the position and speed of an object.

In particular, the FMCW (continuous wave) type millimeter wave sensor can detect motion in units of 0.1 mm at the minimum (for example, Non-Patent Document 1).

C. Iovescu, 1 outside, "Basics of Millimeter Wave Sensor", Texas Instruments Japan Ltd., 2017, [Search on June 22, 2nd year of Reiwa], Internet <URL: https://www.ti. com / jp / lit / wp / jajy058 / jajy058.pdf? ts = 1592807359489 & ref_url = https% 253A% 252F% 252Fwww.google.com% 252Fl>

For example, in a long-term care facility, when monitoring the behavior of a plurality of elderly people using a millimeter-wave sensor, the millimeter-wave sensor determines whether or not a person exists in the monitoring area and what kind of behavior the person is taking. Can be detected. However, who exists and who is taking what kind of action cannot be detected by a device using a conventional millimeter-wave sensor.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a monitoring device capable of identifying an individual with a simple configuration.

In order to solve the above problems, the present invention includes the following aspects.
Item 1.
It is a monitoring device for monitoring multiple individuals.
A millimeter wave sensor that irradiates the individual with millimeter waves,
An identification unit that identifies the individual based on the measurement result of the millimeter wave sensor,
Equipped with
The identification unit is a monitoring device characterized by identifying the individual based on the amplitude of a regularly vibrating portion of the individual.
Item 2.
Item 2. The monitoring device according to Item 1, wherein the site is an artery.
Item 3.
Item 2. The monitoring device according to Item 2, wherein the site is a carotid artery.
Item 4.
Item 6. The monitoring device according to any one of Items 1 to 3, wherein the site is a pleura or a peritoneum.
Item 5.
Item 2. The monitoring device according to any one of Items 1 to 4, wherein the identification unit further identifies the individual based on the height of the individual.
Item 6.
Item 6. The monitoring device according to any one of Items 1 to 5, wherein the frequency band of the millimeter wave is 60 GHz to 64 GHz.
Item 7.
Item 6. The monitoring device according to Item 1 to 6, further comprising a tracking unit for tracking the position of the individual.
Item 8.
A monitoring method comprising monitoring an individual in a specific area by the monitoring device according to any one of Items 1 to 7.
Item 9.
Item 8. The monitoring method according to Item 8, wherein the area is a long-term care facility or a hospital.
Item 10.
A monitoring program that operates a computer as the identification unit of the monitoring device according to any one of Items 1 to 6.

According to the present invention, it is possible to provide a monitoring device capable of identifying an individual with a simple configuration.

It is a schematic diagram of the monitoring system which concerns on 1st Embodiment of this invention. It is a block diagram of the monitoring apparatus which concerns on 1st Embodiment of this invention. This is an example of pattern information. It is a schematic diagram of the monitoring system which concerns on the 2nd Embodiment of this invention. It is explanatory drawing of the detection area of a sensor.

[First Embodiment]
Hereinafter, the first embodiment of the present invention will be described with reference to the accompanying drawings. The present invention is not limited to the following embodiments.

(overall structure)
In the present embodiment, a mode in which the monitoring device according to the present invention is used for monitoring (watching) a resident in a nursing care facility will be described. FIG. 1 is a schematic diagram of a monitoring system 100 according to the present embodiment. The monitoring system 100 includes a plurality of monitoring devices 1 and a server 10. The monitoring device 1 is installed in each room, corridor, rest area, entrance, etc. of the nursing facility. The server 10 is provided in the room where the manager of the long-term care facility is stationed, and can communicate with the monitoring device 1 via a network N such as a LAN. The server 10 controls each monitoring device 1 and detects the behavior of the resident of the long-term care facility based on the information from the monitoring device 1. This makes it possible to implement a monitoring method in which the resident in the long-term care facility is monitored by the monitoring device 1.

(Configuration of monitoring device)
FIG. 2 is a block diagram of the monitoring device 1 according to the present embodiment. The monitoring device 1 is a device constituting an FMCW (continuous-wave radar) type millimeter-wave radar system, and mainly includes a millimeter-wave sensor 2 and a microcomputer 3.

The millimeter wave sensor 2 mainly includes n transmitting antennas TX1 to TXn, n receiving antennas RX1 to RXn, a synthesizer 21, a mixer 22, and an ADC 23. The number (n) of the transmitting antenna and the receiving antenna is not particularly limited, but the larger the number, the more individuals (residents) can be measured at the same time. In this embodiment, n = 5.

The synthesizer 21 generates a modulated wave (chirp signal) whose frequency changes linearly with the passage of time. In the present embodiment, the frequency band of the chirp signal is 60 GHz to 64 GHz.

The chirp signal is transmitted via the transmitting antennas TX1 to TXn in a time division multiplexing (TDM) method, and the receiving antennas RX1 to RXn receive the reflected wave from the individual. The mixer 22 mixes the transmitted wave and the received wave to generate an IF (intermediate frequency) signal. The IF signal is converted into a digital signal by the ADC 23 and input to the microcomputer 3.

The microcomputer 3 mainly includes an auxiliary storage device 31, a CPU 32, and a main storage device (not shown). In the present embodiment, the millimeter wave sensor 2 and the microcomputer 3 are integrated, but at least a part of the functions of the microcomputer 3 may be provided in the server 10 shown in FIG.

The auxiliary storage device 31 is composed of a non-volatile memory such as an EEPROM or a flash memory. The monitoring program 311 and the pattern information 312 are stored in the auxiliary storage device 31. The monitoring program 311 may be supplied via a communication network or may be supplied via a recording medium readable by a computer. The pattern information 312 will be described later.

The CPU 32 operates as a waveform generation unit 321, a DSP 322, an identification unit 323, and a gesture discrimination unit 324 by reading the monitoring program 311 into the main storage device and executing it. Further, at least a part of each functional block of 321 to 324 may be realized in terms of hardware by a logic circuit formed on an integrated circuit (IC chip).

The waveform generation unit 321 has a function of setting the waveform of the chirp signal generated by the synthesizer 21. Specifically, the waveform generation unit 321 sets the start frequency, bandwidth, duration, and the like of the chirp signal.

The DSP322 has a function of acquiring the position and speed of an individual by performing various signal processing (Fourier transform, etc.) on the AD-converted IF signal and detecting the distance, speed, and angle of the individual. .. Methods for detecting the distance, speed, and angle of an individual are conventionally known, and for example, the method described in Non-Patent Document 1 can be adopted. In this embodiment, the position and velocity of a plurality of sites including the carotid artery and the pleura of an individual are detected.

Further, in the present embodiment, the transmitting antenna and the receiving antenna have a known MIMO (multi-input, multi-output) configuration. This makes it possible to simultaneously acquire the positions and velocities of a plurality of individuals.

The identification unit 323 has a function of identifying an individual (that is, identifying who the individual is) based on the measurement result of the millimeter wave sensor 2, that is, information on the position and velocity of the individual. In particular, the identification unit 323 is characterized in that the individual is identified based on the amplitude of the regularly vibrating portion of the individual in the information on the position and velocity of the individual. In this embodiment, the sites that vibrate regularly are the carotid artery and pleura.

The carotid artery and pleura vibrate regularly with heartbeat and respiration, respectively. A person's heart rate and respiratory rate fluctuate, but the carotid and pleural amplitudes are constant regardless of changes in heart rate and respiratory rate. That is, the carotid and pleural amplitudes are unique to each individual. In addition, the carotid artery and pleura have a large impedance difference from other tissues, so that they tend to reflect millimeter waves. Focusing on these, the inventor of the present application has found that an individual can be identified by using a millimeter-wave sensor by using the amplitudes of the carotid artery and the pleura as an index for identifying the individual.

Further, the identification unit 323 identifies the individual based on the height of the individual in addition to the carotid artery and the pleura. By adding height to the index for identifying individuals, even if multiple individuals with the same carotid artery and pleural amplitude are detected, individuals with different heights can be identified, so identification accuracy can be improved. Can be improved.

In the present embodiment, the amplitudes of the carotid artery and the pleura are measured in advance using a millimeter-wave sensor for all the residents of the long-term care facility, or at least all the residents of the room in which the monitoring device 1 is installed. The pattern information 312 is created by associating the information of each resident's number, name, and height with this, and the pattern information 312 is stored in the auxiliary storage device 31 of the monitoring device 1.

An example of the pattern information 312 is shown in FIG. The amplitude of the carotid artery is generally in the range of 0.1 mm to 0.5 mm, and the amplitude of the pleura is in the range of approximately 0.5 mm to 5.0 mm.

The millimeter wave sensor 2 can measure the position of each part of an individual in units of 0.1 mm. In this embodiment, the DSP 322 measures the position and velocity of the carotid artery and pleura of the individual, as well as the position and velocity of 12 points in the height direction and 12 points in the horizontal direction of the individual. In this measurement result, the identification unit 323 calculates the amplitude of the carotid artery and the pleura based on the positions and velocities of the carotid artery and the pleura, and determines the height of the individual based on the positions at both ends in the height direction of the individual. calculate. Further, the identification unit 323 queries the pattern information 312 for the calculated carotid artery and pleural amplitude and height, and identifies a resident who matches (or resembles a predetermined value or more) those numerical values. Thereby, the identification unit 323 can identify which resident the measured individual is.

The gesture discrimination unit 324 has a function of discriminating the movement of the individual identified by the identification unit 323. As a method for discriminating the movement, a conventionally known method can be adopted, and in the present embodiment, the movement of the individual (wake up, sleep, sit, sit) is obtained from the positions and speeds of 12 points in the height direction and 12 points in the horizontal direction of the individual. (Walking, running, etc.) can be determined.

As described above, the monitoring device 1 according to the present embodiment can grasp who exists in a specific area of the long-term care facility and who is taking what kind of action. Further, since the millimeter wave sensor is simpler and cheaper than a general surveillance camera, it is possible to identify an individual with a simple configuration. Further, the surveillance system 100 shown in FIG. 1 can be constructed at a lower cost than a surveillance system using a surveillance camera.

(Additional notes)
Although the first embodiment of the present invention has been described above, the present invention is not limited to the above embodiment, and various modifications can be made without departing from the spirit of the present invention.

In the above embodiment, the identification unit 323 identifies the individual based on the amplitude of the carotid artery and pleura of the individual, but the site that is an index for identifying the individual is a site that regularly vibrates with the amplitude peculiar to the individual. If so, it is not particularly limited. For example, arteries relatively close to the skin, such as the radial artery, ulnar artery, brachial artery, superficial temporal artery, patellar artery, and dorsalis pedis artery, are preferable as an index for identifying an individual because millimeter waves are likely to be incident. In addition to the pleura, the peritoneum can be mentioned as a site that vibrates regularly in response to respiration.

In the above embodiment, the frequency band of the millimeter wave emitted from the millimeter wave sensor 2 is 60 GHz to 64 GHz, but the present invention is not limited to this, and may be, for example, 77 GHz to 81 GHz. However, since this frequency band is often used for collision prevention systems of automobiles and the like, 60 GHz to 64 GHz is preferable from the viewpoint of preventing interference.

[Second Embodiment]
Hereinafter, the second embodiment of the present invention will be described with reference to the accompanying drawings. The members having the same functions as those in the first embodiment are designated by the same reference numerals, and detailed description thereof will be omitted.

FIG. 4 is a block diagram of the monitoring device 1'according to the present embodiment. The monitoring device 1'mainly includes a millimeter wave sensor 2 and a microcomputer 3'.

The millimeter wave sensor 2 may be the same as that shown in FIG. 2, but in the present embodiment, for example, a millimeter wave can be applied to a fan-shaped range having an angle of 116 degrees and a reach of 6 m.

The microcomputer 3'is the one in which the CPU 32 is replaced with the CPU 32' in the microcomputer 3 shown in FIG. 2, and the CPU 32'is the one in which the gesture determination unit 324 is replaced with the tracking unit 325 in the CPU 32. The CPU 32'may further include a gesture determination unit 324.

The tracking unit 325 has a function of tracking the position of an individual. As shown in FIG. 5, the detection region of the sensor 2 is subdivided into a large number (for example, 256) of grid-like masses M. The tracking unit 325 identifies in which of the subdivided cells the individual detected by the DSP 322 is located.

In FIG. 5, the squares M1 to M4 shown by the solid line frame indicate the squares in which the individual is located. Further, the tracking unit 325 identifies who is in which cell by associating each of the cells M1 to M4 with the identification result by the identification unit 323 in the order of proximity to the sensor 2. The method for identifying an individual by the identification unit 323 is the same as that in the first embodiment, and the individual is identified based on the amplitude at the two feature points of the carotid artery and the pleura.

In this way, the tracking unit 325 periodically (for example, every 0.5 seconds) processes the identification of the mass in which the individual exists and the association between the mass and the identification result of the individual, in real time. The position of the individual can be tracked. The position and identification information of the individual identified by the tracking unit 325 may be stored in the memory of the microcomputer 3 in real time and transmitted to the server 10. As a result, the server 10 can manage the position and identification information of the individual in the entire area where the sensor 2 of the facility is provided. The location and identification information of the individual in the facility may be further transmitted to the cloud server that manages a plurality of facilities.

Once an individual is identified, in principle, the identification unit 323 does not identify the individual, and the tracking unit 325 tracks each individual based on the temporal change of the squares M1 to M4 in which the individual is present. For example, when the square shown by the solid line frame in FIG. 5 moves to an adjacent square, the tracking unit 325 presumes that the same individual has moved. On the other hand, if a plurality of individuals move to the same square and then each individual moves to a different square, it becomes impossible to estimate which individual has moved to which square, so that the individual can be identified again by the identification unit 323. This is done and the tracking unit 325 associates the mass with the individual identification result. This allows the tracking unit 325 to continue tracking the individual.

When an individual moves out of the detection area of the sensor 2, the tracking unit 325 cannot track the individual. In that case, the server 10 presumes that the individual has left the room in which the sensor 2 is installed. After that, when the individual enters another room, the sensor 2 installed in the other room identifies the individual and identifies the position in the same manner as described above, and the tracking is restarted. If the sensor 2 installed in another room does not store the pattern information for identifying the individual, the sensor 2 accesses the pattern information of all the individuals stored in the server 10. Can identify the individual. As a result, the server 10 can grasp the movement status of the individual in the facility.

By installing the sensor 2 not only in each room but also in a corridor, a rest room, or the like, the server 10 can almost always track each individual in the facility.

(Additional notes)
Although the second embodiment of the present invention has been described above, the present invention is not limited to the above embodiment, and various modifications can be made without departing from the spirit of the present invention.

The present invention is particularly suitable for monitoring human behavior in nursing care facilities and hospitals, but the monitoring area is not particularly limited. The present invention can also be applied to monitoring animals such as pets. That is, the "individual" to be monitored by the present invention may include animals other than humans.

1 Monitoring device 1'Monitoring device 2 Millimeter wave sensor 21 Synthesizer 22 Mixer 23 ADC
3 Microcomputer 3'Microcomputer 31 Auxiliary storage device 32 CPU
32'CPU
311 Monitoring program 312 Pattern information 321 Waveform generator 322 DSP
323 Identification unit 324 Gesture discrimination unit 325 Tracking unit 10 Server 100 Monitoring system M Mass M1 to M4 Mass RX1 to RXn Receiving antenna TX1 to TXn Transmitting antenna

Claims (10)

It is a monitoring device for monitoring multiple individuals.
A millimeter wave sensor that irradiates the individual with millimeter waves,
An identification unit that identifies the individual based on the measurement result of the millimeter wave sensor,
Equipped with
The identification unit is a monitoring device characterized by identifying the individual based on the amplitude of a regularly vibrating portion of the individual. The monitoring device according to claim 1, wherein the site is an artery. The monitoring device according to claim 2, wherein the site is a carotid artery. The monitoring device according to any one of claims 1 to 3, wherein the site is a pleura or a peritoneum. The monitoring device according to any one of claims 1 to 4, wherein the identification unit further identifies the individual based on the height of the individual. The monitoring device according to any one of claims 1 to 5, wherein the frequency band of the millimeter wave is 60 GHz to 64 GHz. The monitoring device according to claim 1 to 6, further comprising a tracking unit for tracking the position of the individual. A monitoring method comprising monitoring an individual in a specific area by the monitoring device according to any one of claims 1 to 7. The monitoring method according to claim 8, wherein the area is a long-term care facility or a hospital. A monitoring program that operates a computer as the identification unit of the monitoring device according to any one of claims 1 to 6.

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