WO2018216363A1 - Care support system and radio wave control method - Google Patents

Abstract

This care support system includes a sensor unit and an emission control unit. The sensor unit is disposed in a housing of a moving body detection unit installed in a room of a subject, and detects biological information related to the subject by emitting and receiving radio waves. The emission control unit makes the sensor unit detect a noise level by receiving the radio waves while the emission frequency of the radio waves is being changed when the biological information is not being detected. The emission control unit sets, as the emission frequency of the radio waves to be emitted from the sensor unit when detecting the biological information, an emission frequency at which the detected noise level is lower than a prescribed level at which the biological information can be detected.

Description

Care support system and radio wave control method

The present invention provides a care support system in which a sensor unit disposed in a casing of a moving object detection unit installed in a subject's living room detects biological information (for example, a respiratory state) of the subject by radiating and receiving radio waves. And a radio wave control method for controlling the radiation frequency of radio waves.

Conventionally, various Doppler sensors that detect the movement of an object by radiating a radio wave toward the object and receiving a reflected wave reflected by the object and Doppler shifted have been proposed. In such a Doppler sensor, in order to improve detection accuracy, it is necessary to reduce unnecessary noise called a clutter (a reflected wave from an object other than the detection target) as much as possible. Therefore, in Patent Document 1, for example, a signal acquired in a state where there is no object to be detected (a state in which only clutter exists) and a state in which an object to be detected exists (a state in which an object and clutter exist) are acquired. By taking the difference from the signal, the clutter signal that becomes noise is removed.

JP 2006-3289 A (refer to claim 1, paragraphs [0022], [0023], etc.)

In recent years, for the purpose of supporting the daily life of a subject such as a care recipient in a nursing facility or a hospital, the state of the subject is detected using a Doppler sensor (hereinafter also referred to as a sensor unit). However, a care support system that manages this with a server is being used. Even in such a care support system, it is desired to increase the detection accuracy in the sensor unit, but it is not appropriate to apply the method of Patent Document 1 described above at this time for the following reason.

The method described in Patent Document 1 is effective only when the signal to be observed (the reflected wave from the object) is larger than the clutter signal. When the signal to be observed is smaller than the clutter signal, the signal to be observed is buried in the clutter signal. Therefore, when the subtraction process is performed, the signal to be observed cannot be detected. In particular, in elderly care facilities, elderly people are often resident, and in the case of elderly people, a signal (for example, a respiratory signal) detected by the sensor unit is smaller than that of middle-aged and young people. For this reason, the signal (breathing signal) to be observed is often smaller than the clutter signal. Therefore, in the care support system, a method of removing the clutter signal by subtraction processing cannot be adopted.

Also, in nursing care facilities, there are many cared people who spend most of their day in the room due to reasons such as aging and physical disabilities. For this reason, in the care support system constructed in the care facility, it is not possible to freely create a situation in which no care recipient exists in the room and only the clutter exists. For this reason, in the use of the care support system, it is difficult to use the method of Patent Document 1 that intentionally creates a situation where only clutter exists and performs the subtraction process.

In the care support system, the sensor unit (Doppler sensor) is covered with a casing, and is installed on the ceiling of a living room, for example. And the direction of a sensor part is normally adjusted so that it may face the direction of the bed and the futon in a living room (in order to detect the respiratory state in bedtime). When the orientation of the sensor unit is adjusted, the relative positional relationship (for example, the relative distance) between the sensor unit and the housing in front of the sensor unit changes. Therefore, when the radiation frequency of the radio wave radiated from the sensor unit is constant, the sensor Depending on the orientation of the part, unnecessary reflected waves (clutter) radiated from the sensor part and reflected by the inner surface of the housing and returning to the sensor part increase, and the detection performance varies depending on the orientation of the sensor part. Therefore, it is desired to suppress an increase in noise caused by a change in the relative position with respect to the housing, and to suppress a variation in detection performance due to the orientation of the sensor unit, regardless of the orientation of the sensor unit.

The present invention has been made in order to solve the above-described problems. The object of the present invention is to reduce detection accuracy in a sensor unit (Doppler sensor) by reducing clutter as noise without performing subtraction processing of the clutter signal. An object of the present invention is to provide a care support system and a radio wave control method that can suppress variation in detection performance due to the orientation of a sensor unit.

A care support system according to one aspect of the present invention is disposed in a casing of a moving object detection unit installed in a subject's room, and detects a biological information of the subject by emitting and receiving radio waves, A radiation control unit that controls a radiation frequency of the radio wave, and the radiation control unit is configured to detect a noise level at the sensor unit by receiving the radio wave while changing the radiation frequency of the radio wave when the biological information is not detected. And a radiation frequency at which the detected noise level is smaller than a predetermined level at which the biological information can be detected is set as a radiation frequency of a radio wave radiated from the sensor unit when the biological information is detected. .

A radio wave control method according to another aspect of the present invention is provided in a sensor unit that is disposed in a casing of a moving object detection unit installed in a subject's room and detects biological information of the subject by radiation and reception of radio waves. A noise detecting step of detecting a noise level by receiving the radio wave while changing a radiation frequency of the radio wave when the biometric information is not detected, and the detected noise level is a predetermined value capable of detecting the biometric information. A setting step of setting a radiation frequency that is smaller than a level as a radiation frequency of a radio wave radiated from the sensor unit when the biological information is detected.

In the care support system, the clutter signal subtraction process is not performed in post-processing, and noise clutter can be reduced to increase detection accuracy at the sensor unit, and variations in detection performance due to the orientation of the sensor unit can be suppressed. .

It is explanatory drawing which shows the structure of the outline of the care support system which concerns on one Embodiment of this invention. It is explanatory drawing which shows typically the mode in the living room where the moving body detection unit of the said care support system was installed. It is explanatory drawing which shows typically the mode of the living room in which the 2nd electromagnetic wave detection part was installed. It is a block diagram which shows the schematic structure of the said moving body detection unit. It is a block diagram which shows the detailed structure of the optical detection part which the said moving body detection unit has. It is explanatory drawing which shows typically an example of the image acquired by imaging | photography with the said optical detection part. It is sectional drawing of the said moving body detection unit and an electromagnetic wave detection part in each of the attachment state of the front cover of the housing | casing of the said moving body detection unit, and a detached state. It is explanatory drawing which shows an example of the Fourier-transform spectrum of the detection signal when it is unmanned output from the said electromagnetic wave detection part. It is explanatory drawing which shows the Fourier-transform spectrum of a detection signal when the care receiver's respiratory state is detected. It is explanatory drawing which shows typically the generation path | route of the clutter signal which generate | occur | produces inside the moving body detection unit shown in FIG. It is explanatory drawing which shows typically the relationship between the magnitude | size of the respiration signal detected by the sensor part of the said electromagnetic wave detection part, and a noise level. It is explanatory drawing which shows the magnitude | size of a clutter signal for the Fourier-transform spectrum of the signal detected by the said sensor part at the time of unattended. It is explanatory drawing which shows the Fourier-transform spectrum of the detection signal in the said sensor part in case a clutter signal is larger than the power level of a respiration signal. It is explanatory drawing for demonstrating the interference phenomenon of a wave. It is explanatory drawing which shows direction of the said sensor part which changes according to the position of the some bed in a living room. It is explanatory drawing which shows an example of the relationship between a radome angle and a noise level. It is explanatory drawing which shows typically each waveform of a transmission wave, a reflected wave, and a synthetic wave at the time of changing the radiation frequency of a transmission wave. It is explanatory drawing which shows the radome angle dependence of the noise level in a different radiation frequency. It is a block diagram which shows the structure of the care support system of a specific example. It is a flowchart which shows the flow of operation | movement in the said care support system. It is a table which shows the correspondence of each radiation frequency and the detected noise level. It is a graph which shows the relationship between each radiation frequency and the said noise level. It is a graph which shows the said noise level compared with a predetermined level.

An embodiment of the present invention will be described below with reference to the drawings.

[Outline of care support system]
FIG. 1 is an explanatory diagram showing a schematic configuration of a care support system 1 of the present embodiment. The care support system 1 is a system for supporting the daily life of a cared person living in a nursing facility or a general house, or a patient admitted to a hospital (nurse), and is also called a monitoring system. It is. The cared person and the cared person are objects to be supported by the care support system 1, that is, a target person (subject) managed by recognition or detection in the image recognition system 20 or the radio wave detection unit 30 described later. . Here, as an example, a case where the care support system 1 is constructed in a care facility will be described.

In the nursing facility, a staff station 100 and a living room 101 are provided. The staff station 100 is a so-called stuffing station for caregivers who support the lives of the care recipients who spend at the care facilities. The staff station 100 is provided with a management server 100a and a display unit 100b. The management server 100a is a terminal device that is communicably connected to a later-described moving object detection unit 10 installed in the living room 101 via the communication line 200, and includes a central processing unit (CPU; Central Processing Unit). Composed. The communication line 200 is configured by, for example, a wired LAN (Local Area Network), but may be a wireless LAN.

The management server 100a receives and manages various types of information transmitted (output) from the moving body detection unit 10 (for example, a captured image in the living room 101 and biological information of the care recipient) via the communication line 200, The received information is displayed on the display unit 100b. Thereby, the caregiver of the care facility can grasp the state in the living room 101 and the biological information of the care recipient by looking at the information displayed on the display unit 100b. The display unit 100b can be configured by a display of a personal computer, for example. In addition, when it is recognized that an operation of the cared person is abnormal, such as when the cared person falls on the floor by an image recognition process in the image recognition system 20 described later, the management server 100a moves the moving object detection unit. 10 is transmitted to the mobile terminal owned by the caregiver and the data of the captured image in the living room 101 acquired by the optical detection unit 23 of the moving object detection unit 10 is received. It is also possible to inform the caregiver. Note that, when image data is transmitted from the management server 100a to the portable terminal, the size and resolution of the image are appropriately adjusted.

At least one living room 101 is provided in a care facility, and FIG. 1 shows a case where two living rooms 101 are provided as an example. In each living room 101, one bed 102 used by a care recipient is installed. In addition, when two or more care recipients move in one living room 101, a plurality of beds 102 corresponding to each of the care recipients are installed.

FIG. 2 is an explanatory diagram schematically showing the inside of the living room 101 in which the moving object detection unit 10 is installed. As shown in FIGS. 1 and 2, the moving body detection unit 10 is installed on the ceiling portion 101 a of each living room 101 and is communicably connected to a communication line 200. When the living room 101 is a multi-bed room in which a plurality of beds 102 are installed, the moving object detection unit 10 is installed on the ceiling 101 a of the living room 101 corresponding to each bed 102.

The care support system 1 described above includes a moving body detection unit 10 (at least one moving body detection unit 10) installed in at least one living room 101 and a management server 100a provided in the staff station 100 via a communication line 200. Are connected to communicate with each other.

[Motion detection unit]
Next, the details of the moving object detection unit 10 will be described. FIG. 3 is a block diagram showing a schematic configuration of the moving object detection unit 10. The moving body detection unit 10 is a unit that detects information on a cared person in the living room 101, and includes an image recognition system 20, a radio wave detection unit 30, and a unit control unit 40 in a housing 11 (see FIG. 6). Yes. Since the moving body detection unit 10 includes various sensors such as the above-described radio wave detection unit 30 and an optical detection unit 23 described later, it is also called a sensor box.

The image recognition system 20 includes an illumination unit 21, an illumination control unit 22, and an optical detection unit 23. The illumination unit 21 includes an LED (LightＬＥＤEmitting Diode) that emits infrared light (for example, near-infrared light) to enable photographing in the dark, and is provided at the center of the ceiling 101a of the living room 101. Located to illuminate the interior of the living room 101. For example, the illumination unit 21 has a plurality of LEDs and illuminates a floor surface 101b (see FIG. 2) in the living room 101 and a wall connecting the ceiling portion 101a and the floor surface 101b. The illumination control part 22 is comprised, for example with CPU, and controls the illumination (infrared light emission) by the illumination part 21. FIG.

The optical detection unit 23 is an imaging unit that captures an image of the interior of the living room 101 under the illumination of the illumination unit 21 and is configured by a camera, for example. FIG. 4 is a block diagram illustrating a detailed configuration of the optical detection unit 23, and FIG. 5 schematically illustrates an example of an image acquired by photographing with the optical detection unit 23. The optical detection unit 23 is disposed adjacent to the illumination unit 21 in the center of the ceiling 101a (see FIG. 2) of the living room 101, and acquires an image of a viewpoint directly above that has a viewing direction immediately below by photographing. The optical detection unit 23 includes a lens 51, an image sensor 52, an AD conversion unit 53, an image processing unit 54, and a control calculation unit 55.

The lens 51 is, for example, a fixed focus lens, and is configured by a general super wide angle lens or fisheye lens. As the super wide angle lens, a lens having a diagonal angle of view of 150 ° or more can be used. As a result, as shown in FIG. 5, the entire living room 101 can be photographed from the ceiling 101a, and the care recipient in the room and the entire room can be photographed without blind spots.

The imaging element 52 is configured by an image sensor such as a CCD (Charge Coupled Device) or CMOS (Complementary Metal Metal Oxide Semiconductor). The image sensor 52 is configured by removing the IR cut filter so that the state of the cared person can be detected as an image even in a dark environment. An output signal from the image sensor 52 is input to the AD conversion unit 53.

The AD conversion unit 53 receives an analog image signal of an image captured by the image sensor 52 and converts the analog image signal into a digital image signal. The digital image signal output from the AD conversion unit 53 is input to the image processing unit 54.

The image processing unit 54 receives the digital image signal output from the AD conversion unit 53 and executes image processing such as black correction, noise correction, color interpolation, and white balance on the digital image signal. . The image-processed signal output from the image processing unit 54 is input to the image recognition unit 25 described later.

The control calculation unit 55 executes calculations such as AE (Automatic Exposure) related to the control of the image sensor 52 and controls the image sensor 52 such as exposure time and gain. Moreover, the control calculating part 55 performs control while performing calculations, such as a suitable light quantity setting and light distribution setting, with respect to the illumination part 21, as needed. The control calculation unit 55 may have the function of the illumination control unit 22 described above.

The image processing unit 54 and the control calculation unit 55 are configured by separate CPUs, for example. However, the image processing unit 54 and the control calculation unit 55 may be configured by a single CPU or by dedicated circuits that perform image processing and calculation processing. May be.

The image recognition system 20 described above further includes a storage unit 24 and an image recognition unit 25.

The storage unit 24 is a memory that stores a control program executed by the unit control unit 40 and various types of information, and includes, for example, a RAM (Random Access Memory), a ROM (Read Only Memory), a nonvolatile memory, and the like.

The image recognition unit 25 performs image recognition processing on the image data of the image acquired by the optical detection unit 23. More specifically, the image recognition unit 25 receives a signal after the image processing unit 54 of the optical detection unit 23 performs image processing, extracts the contour of the object, for example, and shapes it by a method such as pattern matching. An image recognition process for recognizing the image is executed. Thereby, the image recognition part 25 can recognize the state of the cared person in the living room 101.

Here, the state of the cared person in the living room 101 is assumed to be rising, getting out of bed, entering the floor, falling over, and the like. Waking up refers to the state from when the cared person wakes up to wake up on the bed. Getting out of bed refers to the state from when the cared person wakes up on the bed until it gets off the floor and leaves the bed. Entering the floor refers to the movement of the care recipient from the floor to the bed and lying down. Falling refers to an action in which the care recipient falls on the floor. The above-mentioned getting-up, getting-off, getting-in, falling-over is accompanied by the movement of the cared person's body (body movement), and the minute movement detected by the radio wave detection unit 30 (the minute movement of the body by breathing etc.) ).

Note that the image recognition unit 25 can also recognize (understand) the presence or absence of a cared person in the living room 101 by image recognition. For example, if an area that matches the shape pattern of at least a part of the cared person's body (including the head, for example) is not detected in the image acquired by photographing, the cared person is placed in the living room 101. When it is recognized and detected that there is no caregiver (absence), it can be recognized that there is a cared person in the living room 101.

The radio wave detection unit 30 is a block that detects a moving object in the room 101 by emitting and receiving radio waves. The reflected wave reflected by Doppler and shifted by Doppler is received by a receiving unit (not shown). Thereby, the radio wave detection unit 30 can detect biological information (information such as a respiratory state, a sleep state, and a heart rate) of the cared person from the received reflected wave.

In addition, when the cared person is breathing (including during sleep), minute movements of the body due to the cared person's breathing (micromotion) occur. For this reason, detecting the care recipient's breathing state and sleep state is the same as detecting the care receiver's micromotion. From this, it can also be said that the radio wave detection unit 30 functions as a microscopic motion detection unit that detects microscopic motion of a care recipient (subject).

The unit control unit 40 controls the operations of the image recognition system 20 and the radio wave detection unit 30, and performs image processing and signal processing on information obtained from the image recognition system 20 and the radio wave detection unit 30, and results obtained Is a control board that outputs to the management server 100a as information on the status of the care recipient. The unit control unit 40 includes a main control unit 41, an information processing unit 42, and an interface unit 43, and further includes the storage unit 24 and the image recognition unit 25 described above. Note that the storage unit 24 and the image recognition unit 25 may be provided independently of the unit control unit 40.

The main control unit 41 is composed of a CPU that controls the operation of each unit in the moving object detection unit 10. The information processing unit 42 and the image recognition unit 25 may be configured by the above-described CPU (may be integrated with the main control unit 41), or may be another arithmetic unit or a circuit that performs a specific process. It may be configured.

The information processing unit 42 uses a predetermined algorithm for information (for example, image data) output from the optical detection unit 23 of the image recognition system 20 and information (for example, data related to a respiratory state) output from the radio wave detection unit 30. Based on the signal processing. Information obtained by the signal processing is used for image recognition in the image recognition system 20 (particularly, the image recognition unit 25).

The network cable (not shown) of the communication line 200 is electrically connected to the interface unit 43. Information relating to the status of the cared person detected by the moving object detection unit 10 based on images and microwaves is transmitted to the management server 100a via the interface unit 43 and the communication line 200.

[Supplemental information on radio wave detector]
Next, the description of the radio wave detection unit 30 will be supplemented. FIG. 6 is a cross-sectional view of the moving object detection unit 10 and the radio wave detection unit 30 in an attached state and a detached state of the front cover 11a with respect to a main body 11b described later of the housing 11. The radio wave detection unit 30 includes a sensor unit 31 and a radome lens 32.

The sensor unit 31 is a chip composed of a microwave Doppler sensor for individually detecting biological information of a cared person by emitting and receiving radio waves, and is mounted on a substrate 33. The sensor unit 31 includes an RFLSI (high frequency integrated circuit element), and a transmission antenna and a reception antenna for transmitting and receiving radio waves.

The radome lens 32 is a radio wave lens that protects the sensor unit 31 and controls (for example, narrows) the directivity of radio waves radiated from the sensor unit 31, and is located in front of the sensor unit 31 (on the radio wave emission side). It is provided integrally with the sensor unit 31 via the holding unit 34 so as to be positioned. For example, the surface 32a on the sensor unit 31 side is a flat surface, and the surface 32b on the opposite side to the sensor unit 31 is formed of a plano-convex lens having a convex shape on the radio wave radiation side. It is held by the holding part 34 so as to pass through the center. Therefore, the direction of the sensor unit 31 coincides with the direction of the main axis of the radome lens 32.

Here, the main axis of the radome lens 32 is an axis that passes through the center of curvature of the surface 32b of the radome lens 32 and is perpendicular to the surface 32a, and is synonymous with the optical axis or rotational symmetry axis. In addition, the angle that defines the “direction of the sensor unit 31” described above is such that the sensor unit 31 has a rotation axis in a direction perpendicular to a horizontal plane (here, the ceiling 101a of the living room 101 where the moving object detection unit 10 is installed). It is defined by the yaw angle when rotating and the pitch angle when the sensor unit 31 rotates with the direction parallel to the horizontal plane as the rotation axis, but here, in order to facilitate understanding of the description, unless otherwise noted , And refers to the pitch angle.

Further, here, when considering two rotation axes perpendicular to each other in a plane parallel to the horizontal plane, the pitch angle that is a rotation angle when rotating around one rotation axis (for example, the left-right direction), and the other It is not necessary to distinguish the yaw angle that is the rotation angle when rotating around the rotation axis (for example, the front-rear direction) (the one rotation axis becomes the other rotation axis by rotation in a direction parallel to the horizontal plane). Therefore, both are treated as a pitch angle in a unified manner.

The casing 11 of the moving object detection unit 10 described above includes a front cover 11a located in front of the radome lens 32 (on the side opposite to the sensor unit 31) and the remaining main body 11b. The front cover 11a is detachably installed on the main body 11b. Thereby, when adjusting the direction of the sensor unit 31 to face the direction of the bed 102 so that the sensor unit 31 detects the respiratory state of the care recipient who is sleeping, as described later, It is possible to remove and adjust the cover 11a. When the adjustment of the orientation of the sensor unit 31 is completed, the front cover 11a is attached to the main body 11b again.

The substrate 33 on which the sensor unit 31 is mounted is fixed to a fixing member 38. And the fixing member 38 is rotatably supported by the support body 39 fixed to the main body 11b of the housing | casing 11 so that the direction of the sensor part 31 can be changed.

[Relationship between sensor direction and noise level]
Next, the relationship between the orientation of the sensor unit 31 and the noise level detected by the sensor unit 31 will be described.

(About noise level)
A signal (data) detected by the sensor unit 31 constituted by a Doppler sensor is obtained as time-series (continuous) amplitude data. By performing Fourier transform on these data, signal analysis in the frequency domain becomes possible. For example, when there is no cared person in the living room 101, the Fourier transform spectrum of the signal detected by the sensor unit 31 is obtained as a waveform as shown in FIG. For convenience, the power level on the vertical axis in FIG. 7 is indicated in an arbitrary unit corresponding to the intensity (dB) of the radio wave detected by the sensor unit 31. The noise level refers to the spectrum shown in FIG. 7, that is, the magnitude (power level) of a signal detected by the sensor unit 31 when the care receiver who is the detection target is not in the living room 101.

On the other hand, when the sensor unit 31 detects the respiratory state of the care recipient sleeping on the bed 102 in the living room 101, the Fourier transform spectrum of the detection signal has a waveform as shown in FIG. The spectrum is such that the respiration signal is added. At this time, the ratio of the signal level at the breathing frequency (about 0.2 Hz (around 12 times / minute)) and the noise level becomes the S / N (signal to noise) ratio, and the larger this S / N ratio, The detection accuracy of the breathing state is increased. When the S / N ratio is large, not only the respiratory frequency but also its harmonic components can be detected.

Therefore, in order to detect a respiration signal with a good S / N ratio, it is desirable that the noise level be as small as possible than the level of the detection signal (respiration signal) of the biological information of the care recipient. That is, in order to increase the detection accuracy of the sensor unit 31, it is necessary to reduce the noise level detected by the sensor unit 31 as much as possible.

Here, as a result of various examinations and analyzes by the inventors of the present application, it is known that the main factor that deteriorates the noise level is the clutter signal. The clutter signal is a received wave that has not been Doppler shifted, that is, a received wave having the same frequency as the radiated radio wave (transmitted wave). Originally, a Doppler sensor is a sensor that detects a reflected wave that is reflected back by a moving object, but the transmitted wave is also a radio wave, so it is directly reflected by a stationary object that is not moving and received by the sensor. There are also reflected waves. The directly reflected wave is called a clutter signal.

Normally, a clutter cancel circuit is built in the Doppler sensor and has a function of canceling the clutter signal by electrical processing using a filter or the like. However, when there is a reflective object in the vicinity of the radio wave transmission unit (transmission antenna) of the sensor, a clutter signal exceeding the capacity that can be canceled by the clutter cancellation circuit is generated.

FIG. 9 schematically shows several generation paths of clutter signals generated inside the moving object detection unit 10 shown in FIG. There are mainly the following three generation paths of the clutter signal.
(1) A path A in which a radio wave transmitted from the transmission antenna of the sensor unit 31 directly enters (leaks) into the reception antenna.
(2) The radio wave transmitted from the transmission antenna of the sensor unit 31 is reflected by the surface 32a on the sensor unit 31 side of the radome lens 32, which is a stationary object located in the very vicinity of the transmission antenna, and directly enters the sensor unit 31. Path B.
(3) A path C in which the radio wave transmitted from the transmission antenna of the sensor unit 31 is reflected by the inner surface of the front cover 11a of the housing 11 that is a stationary object located in the vicinity of the transmission antenna and directly enters the sensor unit 31.

Among the above three paths A to C, the influence of the clutter signal generated in the path C has the greatest influence on the noise compared to the clutter signal generated in the other paths. This is suppressed to some extent by the clutter signal generated in the route A and the route B by the design of the sensor unit 31 and the design of the radio wave detection unit 30 (including the setting of the positional relationship between the sensor unit 31 and the radome lens 32). Although the relative positional relationship between the sensor unit 31 and the front cover 11a is not fixed for the clutter signal generated in the path C (the direction of the sensor unit 31 varies depending on the position of the bed 102 in the living room 101). To control) by design.

Here, FIG. 10 schematically shows the relationship between the magnitude of the respiratory signal detected by the sensor unit 31 and the noise level. The upper diagram shows a case where the noise level is relatively low, and the lower diagram shows noise. The case where the level is relatively large is shown. In the figure, the “magnitude of the respiratory signal” on the horizontal axis represents a respiratory detection spectrum (for example, a respiratory frequency (near 0.2 Hz) in the Fourier transform spectrum of the detection signal shown in FIG. This corresponds to the integrated value (area) in the respiration frequency band of 0.5 Hz, and the person with a small respiration signal (for example, an elderly person) is to the left of the center of the horizontal axis (the person with a normal respiration signal magnitude). A person with a large respiratory signal (for example, a young person) is distributed on the right side with respect to the center of the horizontal axis. The “frequency” on the vertical axis corresponds to the total number (frequency) of people indicating the magnitude of a certain respiratory signal. Moreover, the noise level shown in FIG. 10 is equivalent to the integral value in the said respiration detection area of the signal detected by the sensor part 31 when it is unattended.

As shown in the upper diagram of FIG. 10, if the noise level is sufficiently small with respect to the distribution of the magnitude of the respiratory signal, the respiratory signal can be detected even if the respiratory signal is small (the respiratory signal is not reported). . However, as shown in the lower diagram of FIG. 10, when the noise level is deteriorated (increased) by the clutter signal, the respiratory signal below the noise level is buried in the noise level, so that the respiratory signal cannot be detected (the respiratory signal is lost). ). Therefore, in order to increase the detection accuracy of the respiratory signal, it is necessary to suppress an increase in noise level due to the clutter signal.

FIG. 11 is a Fourier transform spectrum of a signal detected by the sensor unit 31 when there is no cared person in the living room 101, and shows a case where the clutter signal is large and a case where the clutter signal is small. Since noise generated by the clutter signal is white noise generated at all frequencies, when the clutter signal is large, the spectrum is such that the entire power level is offset upward compared to when the clutter signal is small.

FIG. 12 shows a Fourier transform spectrum of the detection signal when the respiratory signal of the care recipient is acquired, and shows a case where the clutter signal is larger than the power level of the respiratory signal to be detected. As shown in the figure, when the level of the respiratory signal to be detected is lower than the noise level raised by the clutter signal, the respiratory signal to be detected is buried in the noise, so that the respiratory signal cannot be detected.

When the noise level is subtracted and the clutter signal is canceled as in Patent Document 1 described above, if the power level of the respiratory signal to be detected is larger than the noise level as shown in FIG. The clutter signal can be canceled. However, as shown in FIG. 12, when the power level of the respiration signal is smaller than the noise level, the respiration signal cannot be detected even if the subtraction process is performed because the respiration signal is buried in noise. In the care support system 1, since it is assumed that elderly persons whose respiratory signals are never large are included in the subject and the clutter signal is also quite large, the clutter signal is canceled by the subtraction process as in Patent Document 1. The method cannot be adopted. Therefore, it is necessary to reduce the clutter signal by a method other than the subtraction process.

By the way, the above clutter signal is considered to be a composite wave of a transmission wave and a reflected wave, similarly to the wave interference phenomenon. In the case of a wave, the synthesized wave becomes stronger or weaker depending on the position of the fixed end. In the case of a clutter signal, the fixed end corresponds to the radome lens 32 (surface 32a) or the front cover 11a of the housing 11 shown in FIG. Therefore, the clutter signal is strengthened or weakened depending on the positional relationship between the radome lens 32 and the front cover 11a and the sensor unit 31 (particularly the transmission antenna). That is, as shown in the upper diagram of FIG. 13, when the fixed end is in a position where the reflected wave at the fixed end is opposite in phase to the transmitted wave (incident wave), the transmitted wave and the reflected wave cancel each other. (A synthesized wave (stationary wave) with zero amplitude is obtained). On the other hand, as shown in the lower diagram of FIG. 13, when the fixed end is at a position where the reflected wave at the fixed end is in phase with the transmitted wave, the transmitted wave and the reflected wave reinforce each other (the amplitude is the transmitted wave). A synthetic wave (stationary wave) that is twice as large is obtained).

FIG. 14 schematically shows the orientation of the sensor unit 31 that changes in accordance with the positions of the plurality of beds 102 in the living room 101. In FIG. 14, the vertical direction perpendicular to the ceiling 101a (horizontal plane) is defined as a reference (0 °), and the pitch angle θ of the sensor unit 31 from the vertical direction (here, the angle of the main axis of the radome lens 32 (the radome angle)). )) Is shown when θ = 0 ° is changed from θ = 0 ° to θ = + 20 ° and θ = + 45 ° according to the position of the bed 102. In the care support system 1, in order to detect the respiratory state of the cared person P lying on the bed 102 by the sensor unit 31 while the cared person P is sleeping, the inside of the moving object detection unit 10 installed in the ceiling part 101a The sensor unit 31 is operated in the direction of the bed 102.

As shown in the figure, even if the orientation of the sensor unit 31 is changed in accordance with the position of the bed 102, the relative positional relationship (relative distance) between the sensor unit 31 (especially the transmission antenna) and the radome lens 32 changes. However, the relative positional relationship (relative distance) between the sensor unit 31 and the front cover 11a changes. This depends on the position of the bed 102 installed in the living room 101 (depending on the distance between the moving object detection unit 10 and the bed 102 and the direction of the bed 102 as viewed from the moving object detection unit 10), and the sensor unit 31 and the front cover 11a. This means that the relative distance between and changes.

Thus, when the relative positional relationship between the sensor unit 31 and the front cover 11a changes depending on the orientation of the sensor unit 31, the position of the fixed end (front cover 11a) shown in FIG. Changes. This means that the magnitude of the clutter signal (amplitude and level of the synthesized wave) varies depending on the direction of the sensor unit 31, and the noise level detected by the sensor unit 31 varies depending on the direction of the sensor unit 31.

FIG. 15 shows an example of the relationship between the radome angle and the noise level. However, in the figure, the radiation frequency (transmission wave frequency) of the radio wave from the sensor unit 31 is constant at A (Hz). The noise level on the vertical axis indicates the integral value of the breath detection interval in the Fourier transform spectrum of the signal detected by the sensor unit 31 when unattended. Since each of the radome angles θ1 to θ4 has a different relative distance between the sensor unit 31 and the front cover 11a, it can be seen that the noise level changes according to the radome angle as shown in FIG. In other words, the noise level depends on the radome angle. With such characteristics, the detected noise level varies (varies) depending on the positional relationship between the moving body detection unit 10 and the bed 102 (the direction of the set sensor unit 31), and the micro body movement detection is performed depending on the direction of the sensor unit 31. There will be a difference in ability.

[Concept of reducing noise level]
In order to suppress the variation in the noise level due to the direction of the sensor unit 31, it is necessary to suppress the change in the detected noise level when the direction of the sensor unit 31 is changed. It may be considered that the position of the front cover 11a serving as the fixed end may be changed to a position where the noise level is reduced (position where the clutter signal can be canceled) for each direction of the portion 31. However, in the moving body detection unit 10, it is practically difficult (almost impossible) to change the position of the front cover 11 a for each direction of the sensor unit 31, and in the direction of the sensor unit 31. It is actually difficult to design the shape of the front cover 11a so that the noise level can be reduced.

So, go back to the nature of the wave and consider again. In the case of a wave, even if the position of the fixed end is the same, the magnitude of the synthesized wave can be reduced by changing the frequency (radiation frequency) of the transmission wave. FIG. 16 schematically shows waveforms of a transmission wave, a reflected wave, and a composite wave when the radiation frequency of the transmission wave is A (Hz), B (Hz), and C (Hz). Note that B = 1.1A and C = 0.9A. As shown in the figure, even if the position of the fixed end is the same, the magnitude (amplitude) of the combined wave changes by changing the radiation frequency of the transmission wave. For example, when the radiation frequencies are B and C, the amplitude of the synthesized wave is 30 to 40% smaller than that of the transmission wave (or reflected wave) than when the radiation frequency is A. This is because the phase of the transmission wave at the fixed end position is changed by changing the radiation frequency.

As shown in FIG. 16, if the position of the fixed end is the same, the magnitude of the synthesized wave, that is, the magnitude of the clutter signal changes when the radiation frequency of the transmission wave changes. Also show different characteristics depending on the radiation frequency. FIG. 17 shows the radome angle dependence of the noise level at different radiation frequencies A and B. In the figure, at the radiation frequency A, the noise level increases as the radome angle increases. At the radiation frequency B, the noise level decreases as the radome angle increases. ing. As a result, when the radome angle is θ1 and θ2, the noise level is minimum at the radiation frequency A, and when the radome angle is θ3 and θ4, the noise level is minimum at the radiation frequency B.

As described above, since the radiation frequency at which the noise level is minimized differs depending on the radome angle, the radiation frequency is changed every time the radome angle is changed (each time the direction of the sensor unit 31 is changed according to the change in the position of the bed 102). If the noise level is actually detected by scanning (changing) once in the range from the lower limit to the upper limit, and the radiation frequency that has the lowest detected noise level is found among the scanned radiation frequencies, detection of the respiratory signal Sometimes, by radiating radio waves from the sensor unit 31 at the found radiation frequency, the respiratory signal can be detected with the noise level minimized. Also, since the noise level can be minimized at any radome angle, variations in detection performance due to the radome angle can be reduced. In the care support system 1 of the present embodiment, the radiation frequency of the radio wave radiated from the sensor unit 31 is set based on such a concept. Hereinafter, a specific example of a characteristic configuration of the care support system 1 of the present embodiment will be described.

〔Concrete example〕
FIG. 18 is a block diagram showing the configuration of the care support system 1 of this example. In the figure, for the sake of convenience, a part of the configuration of the image recognition unit 20 is omitted, but the configuration of the image recognition unit 20 is as shown in FIG. In the care support system 1 of this specific example, the radio wave detection unit 30 described above further includes a radiation control unit 36 and an interface unit 37 in addition to the sensor unit 31 and the radome lens 32 and the like. The radiation control unit 36 is a control unit that controls the radiation frequency of the radio wave in the sensor unit 31, and is configured by a CPU, for example. The interface unit 37 is an interface for inputting / outputting information or control signals to / from the unit control unit 40, and includes an input / output port (terminal).

Moreover, the moving body detection unit 10 includes the optical detection unit 23 and the unit control unit 40 described above. In particular, the unit control unit 40 is communicably connected to the management server 100a via the communication line 200, whereby adjustment completion information indicating that the adjustment of the orientation of the sensor unit 31 has been completed from the management server 100a. Can be obtained. The adjustment of the orientation of the sensor unit 31 described above may be performed by setting the orientation of the sensor unit 102 (initial setting) performed when the moving body detection unit 10 is installed in the living room 101 or changing the position of the bed 102 after the unit is installed. The adjustment (change) of the direction of the corresponding sensor unit 31 is included.

In addition, system users (including a service person who installs the motion detection unit 10) own (carry) an external terminal 300 that can wirelessly communicate with the management server 100a via the communication line 200. Thus, for example, the service person installs the moving body detection unit 10 on the ceiling 101 a of the living room 101, adjusts the orientation of the sensor unit 31, and then provides adjustment completion information to the management server 100 a via the external terminal 300. Is possible. As the external terminal 300, for example, a terminal having at least an input unit such as a multifunctional portable terminal such as a tablet or a smartphone or a notebook personal computer can be assumed.

Also, the image recognition unit 25 of the unit control unit 40 detects the presence / absence (presence / absence) of a care recipient in the living room 101 from the image acquired by the optical detection unit 23 by image recognition. The radiation control unit 36 of the radio wave detection unit 30 controls the radiation frequency of the sensor unit 31 as follows based on the acquisition of the adjustment completion information in the unit control unit 40 and the recognition result in the image recognition unit 25.

FIG. 19 is a flowchart showing a flow of operations in the care support system 1 of a specific example. First, the service person adjusts the orientation of the sensor unit 102 in accordance with the position of the bed 102 in the living room 101, and when the adjustment is completed (S1), the adjustment completion information is sent to the management server 100a by operating the external terminal 300. Is transmitted (S2). In response to this, the management server 100a transmits adjustment completion information to the moving object detection unit 10 (S3). In S <b> 1, when the care recipient sleeps with a futon placed on the floor instead of the bed 102, the service person sets the futon according to the position of the futon in the living room 101 (to face the futon). ) The direction of the sensor unit 31 is adjusted.

When the moving body detection unit 10 (particularly the unit control unit 40) acquires the adjustment completion information from the management server 100a (S4; information acquisition process), the optical detection unit 23 takes a picture of the inside of the living room 101 under the control of the unit control unit 40. Is started (S5; photographing process). And the image recognition part 25 performs image recognition with respect to the image acquired by imaging | photography with the optical detection part 23, and detects the presence or absence of the care receiver in the living room 101 (S6, S7; image recognition process). When a cared person exists in living room 101 (No in S7), the processes after S6 are repeated, and the process does not proceed to the next step until the cared person is absent.

On the other hand, when it is detected that the care receiver is absent (Yes in S7), the radiation control unit 36 of the radio wave detection unit 30 starts scanning the radio wave radiation frequency, and the sensor unit 31 receives the radio wave radiation. The noise level received at is detected (S8). Then, such a noise level is detected while changing the radiation frequency over the entire frequency from the lower limit to the upper limit (S9). In the above-described steps S8 and S9, while the cared person is not present in the living room 101, that is, when the biological information (for example, respiratory information) of the cared person is not detected, the radio wave radiation frequency is changed. This corresponds to the noise detection process in which the sensor unit 31 detects the noise level by receiving the radio wave.

FIG. 20 shows the correspondence between the radiation frequencies f1 to f4 obtained when the radiation frequencies are changed to f1, f2, f3 and f4 (all in Hz) and the detected noise levels N1 to N4. As an example, a table is shown. The noise level indicates an integrated value in a breath detection section in a Fourier transform spectrum of a detected signal (noise signal). In the noise detection step described above, the noise level at that time is acquired for each changed radiation frequency, and a table as shown in FIG. 20 is constructed. The table is stored in the storage unit 24 of the unit control unit 40, for example, but a storage unit may be provided in the radio wave detection unit 30 and stored therein.

When the scan of the radiation frequency is completed in S9, the radiation control unit 36 grasps the radiation frequency that minimizes the detected noise level from the constructed table, and detects the radiation frequency using the detected biological information. It is sometimes set as the radiation frequency of the radio wave radiated from the sensor unit 31 (S10; setting step).

FIG. 21 is a graph showing the relationship between the radiation frequencies f1 to f4 and the noise levels N1 to N4. In the example shown in the figure, the noise level N2 obtained at the radiation frequency f2 is the smallest among the noise levels N1 to N4. For this reason, the radiation control unit 36 sets the radiation frequency f2 at which the noise level is minimum with respect to the direction of the sensor unit 31 adjusted in S1 to the radiation frequency of the radio wave radiated from the sensor unit 31 when detecting biological information. Set as. Thereafter (until the direction of the sensor unit 31 is changed next), when detecting the biological information of the care recipient, the radiation control unit 36 radiates radio waves from the sensor unit 31 at the set radiation frequency, and the radio waves The biological information is detected by receiving.

As described above, when the biological information is not detected, the radiation control unit 36 causes the sensor unit 31 to detect the noise level by receiving the radio wave while changing the radio wave radiation frequency (S8, S9). The radiation frequency that minimizes the noise level is set as the radiation frequency of the radio wave radiated from the sensor unit 31 when detecting biological information (S10). Thereby, in order to detect biological information, when radio waves are radiated from the sensor unit 31 at a set radiation frequency, noise (including clutter) is detected regardless of the direction in which the sensor unit 31 is set in the room 101. A signal (detection signal of biological information) that is reduced from the beginning is obtained. As a result, noise can be reduced without performing post-processing for subtracting the clutter signal from the detection signal as in the prior art, and detection accuracy at the sensor unit 31 can be increased. In addition, since the noise level is small in any direction of the sensor unit 31, it is possible to suppress variation in detection performance depending on the direction of the sensor unit 31.

Further, after obtaining the adjustment completion information, the radiation control unit 36 changes the radiation frequency and causes the sensor unit 31 to detect the noise level. That is, the noise detection process (S8, S9) is performed after the information acquisition process (S4). Thereby, the radiation control unit 36 changes the radiation frequency and changes the noise level only when the radiation frequency needs to be set according to the orientation of the sensor unit 31 after the orientation of the sensor unit 31 is adjusted. In S10, an appropriate radiation frequency can be set according to the orientation of the sensor unit 31.

Moreover, in the information acquisition step of S4, the moving object detection unit 10 acquires the adjustment completion information from the management server 100a. In this case, it is not necessary to detect the completion of the adjustment of the orientation of the sensor unit 31 on the moving body detection unit 10 side.

For example, when adjusting the orientation of the sensor unit 31, it is necessary to remove the front cover 11a from the main body cover 11b. By detecting the attachment / detachment by the detection unit, it is detected whether the adjustment of the orientation of the sensor unit 31 has been completed. it can. In addition, if the reset button is provided in the moving object detection unit 10, the adjustment of the orientation of the sensor unit 31 is completed when the service person presses the reset button after the orientation of the sensor unit 31 is adjusted. Can be detected. Although these methods are also possible, there is a concern that by providing the moving body detection unit 10 with a detection unit and a reset button, the structure of the moving body detection unit 10 may be complicated, increased in size, and increased in cost. As described above, by obtaining the adjustment completion information from the management server 100a, the detection unit and the reset button are not required, and the configuration of the moving object detection unit 10 can be simplified, downsized, and cost can be reduced.

Also, the radiation control unit 36 detects the noise level at the sensor unit 31 by changing the radiation frequency after the image recognition unit 25 detects that the care receiver is absent in the living room 101. That is, the noise detection step (S8, S9) is performed after detecting that the care receiver is absent in the living room 101 in the image recognition step (S6, S7). The noise level is a signal detected by the sensor unit 31 when the cared person is not in the living room 101, and the noise level is detected under the condition that there is no cared person in the living room 101. As described above, by detecting the noise level by scanning the radiation frequency after detecting the absence of the care recipient, it is possible to reliably acquire an appropriate signal as the noise level.

Further, the above-described radome lens 32 of the radio wave detection unit 30 is integrally provided via the sensor unit 31 and the holding unit 34. Thus, no matter how the orientation of the sensor unit 31 is set together with the radome lens 32 according to the position of the bed 102, the direction of the radio wave is appropriately controlled by the radome lens 32, and the orientation of the sensor unit 31 is set. An appropriate radiation frequency can be set to increase the detection accuracy of the sensor unit 31, and variations in detection performance due to the orientation of the sensor unit 31 can be reduced.

In the setting step of S10, the radiation frequency that minimizes the detected noise level is set as the radiation frequency of the radio wave radiated from the sensor unit 31 when detecting biological information. Thereby, when radio waves are radiated at a set radiation frequency so as to detect biological information, the influence of noise including clutter signals can be reduced most, and a signal to be detected by the sensor unit 31 (to be observed) A detection signal of biological information) can be reliably acquired.

Note that the radiation frequency set in S10 is not limited to a radiation frequency that minimizes the noise level detected in S8 and S9. For example, as shown in FIG. 22, even if the radiation frequency is f1, if the noise level N1 is smaller than a predetermined level Nth at which biological information can be detected, such radiation frequency f1 is set to S10. It may be set with. The noise level N1 detected at the radiation frequency f1 is larger than the noise level N2 detected at the radiation frequency f2, but is smaller than a predetermined level Nth at which biological information can be detected, and the level of the respiratory signal to be detected. Therefore, as shown in FIG. 12, the noise level is higher than the level of the respiration signal, and the detection accuracy of the respiration signal can be improved as compared with the case where the respiration signal is buried in the noise level. .

Thus, by setting the radiation frequency set in S10 to a frequency other than the radiation frequency that minimizes the noise level, for example, in each moving body detection unit 10 installed in the adjacent room 101, the noise level is minimized. In the case where the radiation frequencies of the sensor unit 31 are the same, both the radiation frequencies can be set to be shifted from each other. As a result, it is possible to avoid erroneous detection due to radio wave interference, which occurs when the adjacent living rooms 101 have the same radiation frequency.

In the above-described step S7, the presence / absence of a cared person is detected from the image acquired by the optical detection unit 23 by image recognition. The method is not limited. For example, in step S5, the image information acquired by the optical detection unit 23 is transmitted to the management server 100a, the image is displayed on the display unit 100b, and the system user confirms the display screen. You may make it judge the presence or absence of a care receiver. If it is determined that the care receiver is absent, the user operates a control unit (not shown) of the management server 100a (for example, a keyboard of a personal computer) to send a control signal instructing the start of scanning of the radiation frequency to the moving object. By transmitting to the detection unit 10, the moving body detection unit 10 can also start scanning of the radiation frequency by the radiation control unit 36 based on the reception of the control signal.

In addition, although the structure which the radio wave detection part 30 has the radome lens 32 was demonstrated above, the radome lens 32 should just be provided as needed, and installation of the radome lens 32 is also omissible. In the radio wave detection unit 30, when the radome lens 32 is not provided, the direction of the sensor unit 31 may be a direction perpendicular to the substrate 33 on which the sensor unit 31 is mounted. The “radome angle” described above may be read as “the pitch angle of the sensor unit 31”.

The embodiment of the present invention has been described above, but the scope of the present invention is not limited to this, and various modifications can be made without departing from the spirit of the invention. For example, the radiation control unit 36 of the radio wave detection unit 30 may be provided in the unit control unit 40, and the main control unit 41 of the unit control unit 40 also functions as the radiation control unit 36 described above. Also good.

[Others]
The care support system and radio wave control method of the present embodiment described above can be expressed as follows, and thereby have the following effects.

The care support system described in the present embodiment is disposed in a casing of a moving body detection unit installed in a subject's room, and detects a biological information of the subject by emitting and receiving radio waves, A radiation control unit that controls a radiation frequency of the radio wave, and the radiation control unit changes a noise level in the sensor unit by receiving the radio wave while changing the radiation frequency of the radio wave when the biological information is not detected. A radiation frequency at which the detected noise level is smaller than a predetermined level at which the biological information can be detected is set as a radiation frequency of a radio wave radiated from the sensor unit when the biological information is detected.

According to the above configuration, the radiation control unit sets a radiation frequency at which the noise level detected by the sensor unit when the biological information is not detected becomes smaller than a predetermined level as the radiation frequency when the biological information is detected. To do. This reduces noise (including clutter) from the beginning when radio waves are emitted from the sensor unit at the set emission frequency to detect biological information, regardless of the orientation of the sensor unit. Signal (detection signal of biological information) is obtained. Thereby, noise can be reduced without performing post-processing of subtracting the clutter signal from the detection signal as in the prior art, and detection accuracy at the sensor unit can be increased. In addition, since the noise level is small in any direction of the sensor unit, it is possible to suppress variation in detection performance depending on the direction of the sensor unit.

The radio wave control method described in the present embodiment is arranged in a housing of a moving object detection unit installed in the subject's room, and in a sensor unit that detects biological information of the subject by radiation and reception of radio waves, A noise detecting step of detecting a noise level by receiving the radio wave while changing a radiation frequency of the radio wave when the biometric information is not detected; and the detected noise level is higher than a predetermined level at which the biometric information can be detected. And a setting step of setting a radiation frequency that becomes smaller as a radiation frequency of a radio wave radiated from the sensor unit when the biological information is detected. In this case, it is possible to obtain the same effect as the effect of the configuration of the care support system described above.

The care support system further includes a management server that is communicably connected to the moving object detection unit, and the radiation control unit has completed adjustment indicating that adjustment of the orientation of the sensor unit has been completed from the management server After acquiring information, it is desirable to change the radiation frequency and detect the noise level at the sensor unit. Further, in the radio wave control method described above, the moving object detection unit obtains adjustment completion information indicating that the adjustment of the orientation of the sensor unit has been completed from a management server that is communicably connected to the moving object detection unit. It is preferable that the method further includes an acquisition step, and the noise detection step is performed after the information acquisition step.

Since the noise level is detected after the adjustment completion information is acquired, the radiation frequency is used only when it is necessary to set an appropriate radiation frequency according to the sensor unit orientation based on the fact that the sensor unit orientation adjustment is completed. The noise level can be detected by the sensor unit. In addition, since the moving object detection unit acquires the adjustment completion information from the management server, it is not necessary to provide a detection unit that detects the adjustment completion of the orientation of the sensor unit on the moving object detection unit side. Therefore, the configuration of the moving body detection unit can be simplified and the cost can be reduced by the amount that such a detection unit is unnecessary.

In the care support system, the moving body detection unit captures the presence or absence of a subject in the room by image recognition from an image capturing unit that captures an image by capturing an image of the room and an image acquired by the image capturing unit. An image recognizing unit for detecting, and the radiation control unit detects that the subject is absent in the room and then changes the radiation frequency to change the radiation frequency in the sensor unit. It is desirable to detect the noise level. In addition, the radio wave control method further includes a photographing step of photographing a room to acquire an image, and an image recognition step of detecting presence or absence of a subject in the room by image recognition from the image, The noise detection step is preferably performed after detecting that the subject is absent in the room in the image recognition step.

After detecting the absence of the subject by image recognition from the image taken in the room, the sensor unit detects the noise level by changing the radiation frequency, so that an appropriate signal (in the room) The signal detected when the subject is absent can be reliably acquired.

In the care support system, the radiation control unit may set a radiation frequency at which the detected noise level is minimized as a radiation frequency of a radio wave radiated from the sensor unit when the biological information is detected. desirable. Further, in the radio wave control method, in the setting step, a radiation frequency that radiates from the sensor unit when detecting the biological information is set to a radiation frequency that minimizes the noise level detected in the noise detection step. It is desirable to set it as a frequency.

When radio waves are radiated at a set radiation frequency to detect biological information, the noise level detected by the sensor unit is minimized, so a signal to be detected by the sensor unit (detection of biological information to be observed) Signal) can be reliably acquired.

The present invention can be used for a care support system that supports the daily life of a subject such as a care recipient in a living room.

DESCRIPTION OF SYMBOLS 1 Care support system 10 Moving body detection unit 11 Case 11a Front cover 23 Optical detection part (imaging part)
25 Image recognition unit 31 Sensor unit 32 Radome lens 34 Holding unit 36 Radiation control unit 40 Unit control unit 100a Management server 101 Living room 102 Bed

Claims (8)

A sensor unit that is arranged in a housing of a moving object detection unit installed in the subject's room and detects biological information of the subject by radiating and receiving radio waves;
A radiation control unit for controlling the radiation frequency of the radio wave,
The radiation control unit causes the sensor unit to detect a noise level by receiving the radio wave while changing a radiation frequency of the radio wave when the biological information is not detected, and the detected noise level is the biological information. A care support system that sets a radiation frequency that is smaller than a predetermined level at which detection is possible as a radiation frequency of a radio wave radiated from the sensor unit when the biological information is detected. A management server communicatively connected to the motion detection unit;
The radiation control unit acquires adjustment completion information indicating that the adjustment of the orientation of the sensor unit is completed from the management server, and then changes the radiation frequency to cause the sensor unit to detect the noise level. The care support system according to claim 1. The moving object detection unit is
An image capturing unit that captures an image of a room and acquires an image;
An image recognition unit that detects presence or absence of a subject in the room by image recognition from the image acquired by the imaging unit;
The said radiation control part changes the said radiation frequency, and detects the said noise level in the said sensor part, after the said image recognition part detects that a subject is absent in a room. The described care support system. 4. The radiation control unit according to claim 1, wherein the radiation control unit sets a radiation frequency at which the detected noise level is minimized as a radiation frequency of a radio wave radiated from the sensor unit when the biological information is detected. As described in the care support system. A sensor unit, which is disposed in a casing of a moving object detection unit installed in the subject's room and detects biological information of the subject by radiation and reception of radio waves, detects the radio waves when the biological information is not detected. A noise detection step of detecting a noise level by receiving the radio wave while changing a radiation frequency;
A setting step of setting a radiation frequency at which the detected noise level is smaller than a predetermined level at which the biological information can be detected as a radiation frequency of a radio wave radiated from the sensor unit when the biological information is detected. Including radio wave control method. The moving object detection unit further includes an information acquisition step of acquiring adjustment completion information indicating that the adjustment of the orientation of the sensor unit is completed from a management server that is communicably connected to the moving object detection unit,
The radio wave control method according to claim 5, wherein the noise detection step is performed after the information acquisition step. A shooting process of taking an image of the room and acquiring an image;
From the image, further comprising an image recognition step of detecting the presence or absence of a subject in the room by image recognition,
The radio wave control method according to claim 6, wherein the noise detection step is performed after detecting that the subject is absent in the room in the image recognition step. In the setting step, a radiation frequency that minimizes the noise level detected in the noise detection step is set as a radiation frequency of a radio wave radiated from the sensor unit when the biological information is detected. 8. The radio wave control method according to any one of 7.

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