JP2013211779A - Safety supervision device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a safety supervision device configured not to generate radio wave interference when using a wireless LAN that uses a resembling radio wave frequency band and a microwave Doppler sensor.SOLUTION: A safety supervision device (20) includes: a microwave Doppler sensor (30); a frequency switchover unit (34) for switching a use microwave frequency; a safety information acquisition unit (50) for acquiring safety information of a subject by irradiating the subject (10) with a microwave and receiving a reflection wave; a radio transmitter unit (60) for transmitting the safety information by radio communication with an access point (70); and a detector unit (61) for detecting a frequency channel for radio communication. Based on the frequency channel detected by the detector unit, the frequency switchover unit switches a microwave frequency so as not to generate interference with radio communication by the radio transmitter unit.

Description

  The present invention relates to a safety monitoring device, and more particularly to a safety monitoring device that monitors a comprehensive physical condition.

  In recent years, the social structure has become complicated, and an increasing number of people living alone, such as elderly people living alone. A person who lives alone may not be able to grasp the person's state most recently, and thus there is a possibility that safety monitoring such as physical condition may be delayed. For this reason, the importance of the safety monitoring apparatus which checks a physical state using a sensor is increasing.

  Therefore, a system is known that can confirm the safety by detecting the movement of a human body in a room by an infrared sensor and outputting the detected information to an information output terminal via a communication device ( For example, see Patent Document 1).

  However, it is mainly the movement of the human body that can be detected using infrared rays.For example, the state of listening to music without moving without any problems, and the physical state There was a problem that it was difficult to distinguish from a state in which an abnormality occurred and it could not move.

  In addition, a Doppler sensor is known in which microwaves are output from one master unit and reflections from a plurality of slave units are detected by the master unit (see, for example, Patent Document 2). In the Doppler sensor, the amplitude of the reflected wave is set to be different for each slave unit, and the frequency of the IF signal generated by the reflected wave received by the master unit is set to be different for each slave unit. Each signal level change can be monitored individually.

  Furthermore, a wireless LAN system that prevents interference radio waves from being generated by a microwave oven connected to the wireless LAN system is known (see, for example, Patent Document 3). In the above-described system, different radio wave interference model patterns are used according to cooking of the microwave oven to remove the interference radio wave noise so that no interference radio wave is generated.

JP-A-11-346270 JP 2008-298611 A JP 2002-300171 A

  Regulations by the Radio Law are relaxed, and the radio frequency band around 2.4 GHz is open so that it can be used without a radio license. A wireless LAN compliant with IEEE802.11b / g uses the above-described radio frequency band around 2.4 GHz, and is widely recognized and a large number of related products are manufactured. It is possible to introduce a wireless LAN system compliant with 11b / g.

  A microwave refers to an electromagnetic wave in a band of approximately 3 to 30 GHz. For the same reason, a microwave Doppler sensor using a radio frequency band in the vicinity of 2.4 GHz can be easily introduced. However, a safety monitoring device using a wireless LAN using a similar radio frequency band and a microwave Doppler sensor has not been proposed.

  Accordingly, an object of the present invention is to provide a safety monitoring device configured to prevent radio wave interference when a wireless LAN using a similar radio frequency band and a microwave Doppler sensor are used.

  A safety monitoring apparatus according to the present invention includes a microwave Doppler sensor, a frequency switching unit that switches a frequency of a microwave used in the microwave Doppler sensor, and a reflected wave received by irradiating the subject with the microwave. A safety information acquisition unit that acquires the safety information of the examiner, a wireless transmission unit that performs wireless communication with the access point and transmits the safety information, and a frequency channel for the wireless transmission unit to perform wireless communication with the access point The frequency switching unit switches the frequency of the microwave based on the frequency channel detected by the detection unit so as not to cause interference with radio communication by the radio transmission unit.

  Furthermore, the safety monitoring device according to the present invention further includes a noise filter for removing noise, and the detection unit further detects a transfer rate when the wireless transmission unit performs wireless communication with the access point, and the noise filter It is preferable that the noise removal band by is set based on the transfer rate.

  Furthermore, in the safety monitoring apparatus according to the present invention, it is preferable that the detection unit receives a beacon output from an access point and detects a frequency channel.

  Furthermore, in the safety monitoring apparatus according to the present invention, the safety information is preferably a body motion number or respiratory rate of a subject, or a microwave Doppler shift signal from a microwave Doppler sensor.

  The safety monitoring apparatus according to the present invention can be operated so as not to cause radio wave interference even when a wireless LAN using a similar radio frequency band and a microwave Doppler sensor are used. As a result, wireless communication in the wireless LAN is not disabled, and noise is not superimposed on the sensor output of the microwave Doppler sensor so that detection is not possible.

1 is a schematic configuration block diagram of a safety monitoring system 1 including a safety monitoring device 20 according to the present invention. It is a figure which shows an example of the whole processing flow in the safety monitoring system. It is a figure for demonstrating the radio wave interference in an apartment house. It is a figure which shows the channel distribution etc. in a 2.4 GHz band. It is a figure which shows an example of the microwave Doppler shift signal Ma. It is a figure for demonstrating operation | movement of the body motion number detection part. It is a figure for demonstrating operation | movement of the respiration rate detection part. It is a figure for demonstrating the safety pattern As produced | generated in the safety determination part. 2 is an external view showing an example of a notification terminal 110. FIG.

  The safety monitoring device will be described below with reference to the drawings. However, it should be understood that the invention is not limited to the drawings or the embodiments described below.

  FIG. 1 is a schematic block diagram of a safety monitoring system 1 including a safety monitoring device 20 according to the present invention.

  The safety monitoring system 1 includes a safety monitoring device 20, a wireless receiver 70, a network 80 such as a LAN and the Internet, a safety server 90, a notification terminal 110, a communication terminal 120, and the like.

  The safety monitoring device 20 includes a microwave Doppler sensor 30 that irradiates the subject 10 with the microwave M and receives a reflected wave, a signal processing unit 40 that processes a signal from the microwave Doppler sensor 30, and a signal processing unit. Based on the output from 40, the detection part 50 which performs body movement number detection and respiration rate detection, the wireless transmission part 60 for transmitting the data regarding the body movement number and respiration rate which the detection part 50 detected, and the detection part 50 detect The first storage unit 21 that stores the number of body movements and the respiration rate, a time measuring unit 22, a battery (not shown), and the like are included.

  The safety monitoring device 20 is configured as, for example, a small box-shaped component attached near the ceiling, operates with a built-in battery, and can perform communication using a wireless LAN as will be described later. There is no need to do this and it is easy to install.

  The time measuring unit 22 divides a clock signal having a predetermined frequency generated by using a crystal resonator, and outputs a first time measuring signal T1 (pulse signal with a period of 10 msec) to be output to the signal processing unit 40. A second timing signal T2 (pulse signal with a cycle of 30 seconds) to be output to the detection unit 50 and a third timing signal T3 (pulse signal with a cycle of 3 minutes) to be output to the wireless transmission unit 60 are generated. Note that the values of the first time signal T1, the second time signal T2, and the third time signal T3 are merely examples, and other values may be used.

  The microwave Doppler sensor 30 includes a microwave transmitter 31 that transmits the microwave M toward the subject 10, a microwave receiver 32 that receives a reflected wave from the subject 10, the transmitted microwave, and the received wave A microwave demodulator 33 that outputs a microwave Doppler shift signal Ma based on the microwave and a use frequency switching unit 34 are configured.

  The microwave receiver 32 has a detection directivity with a cone angle of ± 60 ° by the backplane. Based on the frequency CN information from the wireless information acquisition unit 61, the use frequency switching unit 34 sets the frequency of the microwave transmitted from the microwave transmitter 31 to 2.403 GHz (first frequency) and 2.475 GHz (second frequency). ). The microwave receiver 32 incorporates two transmitters corresponding to the above two, and the use frequency switching unit 34 switches the frequency by selecting the transmitter to be used.

  The signal processing unit 40 includes a band limiting circuit 41, an A / D conversion circuit 42, and a digital filter 43.

  The band limiting circuit 41 is configured to include a band pass filter for removing unnecessary frequency band components in the microwave Doppler shift signal Ma output from the microwave demodulator 33, and the microwave band limiting signal Output Ms. The A / D conversion circuit 42 performs sampling using the first time signal T1 (pulse signal having a 10 msec cycle) from the time measuring unit 22, and the microwave band limit signal Ms is converted into a digital signal of microwave digital data Md. Convert to and output.

  The digital filter 43 functions to acquire information on a transfer rate from the wireless information acquisition unit 61 and remove a signal in a predetermined frequency band centered on the frequency. Since noise is often applied to a frequency corresponding to a transfer rate when the wireless transmission unit 60 performs wireless transmission, the digital filter 43 functions to remove such noise from the microwave digital data Md. The digital filter 43 is not always necessary when noise due to the transfer rate is small.

  The detection unit 50 includes a body movement number detection unit 51 for detecting the number of body movements based on the microwave digital data Md, and a respiration rate detection unit 52 for detecting the respiration rate based on the microwave digital data Md. Have.

  The body motion number detection unit 51 performs time differentiation on the microwave digital data Md to generate microwave time change rate data Dd, and compares the microwave time change rate data Dd with a predetermined threshold value to obtain an effective body. The subject 10 uses the threshold value comparison circuit 512 that outputs the motion signal Cd, the effective body motion signal Cd, and the second timing signal T2 (pulse signal with a period of 30 seconds) from the timing unit 22 to generate a unit time (30 seconds). It includes a body movement counting circuit 513 that counts and outputs the number of body movements Td corresponding to the number of movements. A detailed method for detecting the body motion number Td will be described later.

  The respiration rate detection unit 52 detects an FFT circuit 521 that performs FFT processing on the microwave digital data Md and outputs frequency distribution data Fs, and a fundamental wave detection circuit 522 that detects fundamental wave data Rf from the frequency distribution data Fs. The respiration counting circuit 523 for detecting the respiration rate Rr per minute from the fundamental wave data Rf is included. A detailed method for detecting the respiratory rate Rr will be described later.

  The wireless transmission unit 60 transmits the body movement number Td and the respiration rate Rr stored in the first storage unit 21 to the wireless reception unit 70 as wireless signal data. The wireless transmission unit 60 has a wireless information acquisition unit 61. The wireless information acquisition unit 61 acquires information on the frequency CH and transfer rate used for transmission / reception, and transfers the acquired frequency CH and transfer rate information to the microwave Doppler sensor 30 and the signal processing unit 40.

  The wireless transmission unit 60 and the wireless reception unit 70 constitute a wireless LAN system that uses a radio frequency band in the vicinity of 2.4 GHz that conforms to IEEE802.11b / g. The wireless reception unit 70 includes a network interface 71 to the network 80 and functions as an access point corresponding to a wireless relay for the wireless transmission unit 60. The wireless receiving unit 70 transmits the data related to the body movement number Td and the respiratory rate Rr received from the wireless transmission unit 60 to the safety server 90 via the network 80 using the network interface 71.

  The safety server 90 includes a data transmission / reception unit 91 that receives data related to the body motion number Td and the respiratory rate Rr via the network 80, a safety determination unit 92 that performs safety determination based on the data related to the body motion number Td and the respiratory rate Rr, And the alerting | reporting part 100 etc. which alert | report the result of safety determination are comprised. In the safety monitoring system 1, a plurality of safety monitoring devices 20 may communicate with one safety server 90.

  The safety determination unit 92 creates and outputs a safety pattern As based on the data related to the body motion number Td and the respiratory rate Rr received from the safety monitoring device 20. The safety pattern As will be described later.

  The alerting | reporting part 100 is the 2nd memory | storage part 101 which memorize | stores the safety pattern As output from the safety determination part 92, and the report which determines whether it reports based on the safety pattern As memorize | stored in the 2nd memory | storage part 101 The determination unit 102 and the communication unit 103 that makes a notification to the notification terminal 110 when the notification determination unit 102 determines to make a notification are included.

  The notification terminal 110 is an information terminal connected to the safety server 90 by radio or wire, and displays the content of the notification by the notification unit 100 on the display unit or from a speaker. The communication terminal 120 is an information terminal connected to the safety server 90 via the network 80, and corresponds to a mobile phone, a PC, or the like. In the safety monitoring system 1, it is not always necessary to have both the notification terminal 110 and the communication terminal 120. In the safety monitoring system 1, one safety server 90 can perform a reporting operation on a plurality of notification terminals 110 and / or a plurality of communication terminals 120.

  FIG. 2 is a diagram illustrating an example of the entire processing flow in the safety monitoring system 1.

  The processing flow shown in FIG. 2 shows the processing flow after the safety monitoring device 20 is activated by a switch (not shown). First, the irradiation of the microwave M from the microwave Doppler sensor 30 is stopped (S10).

  Next, the wireless transmission unit 60 searches for a wireless reception unit 70 (access point) having a predetermined SSID (S11). The SSID can be acquired from the beacon output from the wireless reception unit 70. On the safety monitoring device 20 side, the frequency CH used on the wireless reception unit 70 (access point) side is unknown until beacon information is received.

  Next, the wireless information acquisition unit 61 acquires frequency CH information and transfer rate information used for transmission / reception from a beacon output from the wireless reception unit 70 having a predetermined SSID (S12). Also, the wireless information acquisition unit 61 sets the wireless transmission unit 60 so that wireless communication is performed using the acquired frequency CH information and transfer rate information. Further, the wireless information acquisition unit 61 transfers the acquired frequency CH information and transfer rate information to the microwave Doppler sensor 30 and the signal processing unit 40.

  Next, based on the frequency CH information transferred from the wireless information acquisition unit 61, the use frequency switching unit 34 uses a microwave to be used so as not to interfere with the wireless LAN radio wave used by the wireless transmission unit 60. The frequency of M is selected (S13). The selection of the frequency of the microwave M to be used will be described later.

  Next, the digital filter 43 sets a frequency band for noise removal based on the transfer rate transferred from the wireless information acquisition unit 61 (S14). The signal processing unit 40 is set to remove noise from the microwave digital data Md by the set digital filter.

  Next, the microwave Doppler sensor 30 starts irradiation of the microwave M at the selected frequency (S15), and generates a microwave Doppler shift signal Ma using the irradiated microwave M and the received reflected wave. And output to the signal processing unit 40.

  Next, the body motion detection unit 51 detects the body motion number Td based on the microwave digital data Md output from the signal processing unit 40 (S16), and the respiration rate detection unit 52 outputs from the signal processing unit 40. The respiratory rate Rr is detected based on the microwave digital data Md (S17). Note that the detection order of the body motion number Td and the respiration rate Rr may be reversed or may be obtained in parallel. The detection of the body motion number Td by the body motion number detection unit 51 will be described later with reference to FIG. The detection of the respiration rate Rr by the respiration rate detection unit 52 will be described later with reference to FIG.

  Next, the body motion number Td detected by the body motion number detection unit 51 and the respiration rate Rr detected by the respiration rate detection unit 52 are stored in the first storage unit 21 (S18).

  Next, the wireless transmission unit 60 collects the body motion number Td and the respiration rate Rr at regular intervals stored in the first storage unit 21 at regular intervals (every 3 minutes), and wirelessly transmits them to the radio reception unit 70. It transmits as signal data (S19), and a series of operation | movement of the safety monitoring apparatus 20 is complete | finished. As will be described later, the body motion number Td is detected every 30 seconds, and the respiration rate Rr is detected every minute. However, the wireless transmission unit 60 uses the third time measurement signal T3 (pulse signal with a period of 3 minutes) from the time measurement unit 22 to make a body at regular intervals (every 3 minutes) stored in the first storage unit 21. Control is performed so that the number of motions Td and the number of breaths Rr are collectively transmitted to the safety server 40 at a time.

  In the safety monitoring device 20, S <b> 10 to S <b> 19 are repeatedly executed and controlled such that the body motion number Td and the respiratory rate Rr for a certain interval are transmitted to the safety server 40 at regular intervals (every 3 minutes). ing. That is, the frequency channel of the radio wave used between the safety monitoring device 20 and the wireless reception unit 70 is also confirmed as appropriate, and is reset so as not to cause interference if necessary. This is because the frequency channel to be used may be changed on the wireless reception unit 70 (access point) side according to the surrounding situation.

  Next, the safety server 90 receives the body movement number Td and the respiratory rate Rr from the safety monitoring device 20 via the network 80 (S20).

  Next, the safety determination unit 92 creates and outputs the safety pattern data As based on the received body motion number Td and respiratory rate Rr (S21).

  Next, the report determination unit 102 determines whether or not a report is necessary based on the safety pattern data As (S22). When it is determined that the notification is necessary, the communication unit 103 notifies the notification terminal 110 (S23), and a series of processes in the safety server 90 is completed. If the report determination unit 102 determines to make a report, the data transmission / reception unit 91 may make a report to the communication terminal 120 via the network 80 using e-mail or the like. The safety server 90 repeatedly executes S20 to S23 at the timing when the body motion number Td and the respiratory rate Rr are received from the safety monitoring device 20.

  FIG. 3 is a diagram for explaining radio wave interference in an apartment house.

  In the example of FIG. 3, the safety monitoring device 20 and the wireless reception unit 70 illustrated in FIG. 1 are installed in the residence 1 of the apartment house 2, and another safety monitoring device 20 similar to the safety monitoring device 20 illustrated in FIG. It is assumed that 'and another wireless reception unit 70' are installed.

  There is a possibility that the radio wave O used in the wireless LAN between the microwave M from the safety monitoring device 20 and the wireless transmission unit 60 of the safety monitoring device 20 may reach the wireless reception unit 70. When the radio wave O by the LAN is in the same frequency band, radio wave interference may occur.

  Both the microwave M used by the microwave Doppler sensor 30 and the radio wave O used by the wireless transmission unit 60 have an output with an antenna power of about 10 mW / MHz. That is, it is an output that can obtain a communication distance of about 10 m in a situation where the line of sight is good. In the safety monitoring device 20, since the microwave Doppler sensor 30 and the wireless transmission unit 60 are close to about several tens of centimeters, there is a high possibility that radio wave interference will occur.

  In addition, there is a possibility that the radio wave O ′ used in the other safety monitoring device 20 ′ and the radio receiving unit 70 ′ constituting the other wireless LAN system may reach the radio receiving unit 70, and between the radio wave O and the radio wave O ′. There is a possibility that radio wave interference will occur.

  FIG. 4 is a diagram showing channel distribution and the like in the 2.4 GHz band.

  In the 2.4 GHz band, CHs that can be used in a wireless LAN compliant with IEEE802.11b / g are 13 channels, CH1 to CH13, and the center frequency of each CH is set at intervals of 5 MHz. For example, the center frequency of CH1 is 2.412 GHz, and the center frequency of CH13 is 2.472 GHz. The frequency band used for one channel is 22 MHz. Therefore, it can be used without causing radio wave interference in three different channels. For example, as shown in FIG. 4, three of CH1, CH6, and CH11 can be used for communication at the same time without interference.

  Therefore, interference between the radio wave O and the radio wave O ′ in the wireless reception unit 70 of the residence 1 in FIG. 3 can be prevented by changing the frequency channel used by each. For example, the radio wave O used between the safety monitoring device 20 and the radio reception unit 70 uses the frequency of CH1, and the radio wave O ′ used between the safety monitoring device 20 ′ and the radio reception unit 70 ′ is that of CH11. Use frequency.

  Based on the above-described reason, the frequency channel of the radio wave O used between the safety monitoring device 20 and the radio reception unit 70 may be changed between CH1 to CH13 in order to prevent radio wave interference. Therefore, the frequency of the microwave transmitted from the microwave transmitter 31 can be switched between 2.403 GHz (first frequency) and 2.475 GHz (second frequency) so that the radio wave O and the microwave M do not interfere with each other. It is said. Specifically, when the frequency channel of the radio wave O used between the safety monitoring device 20 and the wireless receiving unit 70 is CH7 to CH13, 2.403 GHz (first frequency) is used, and the frequency channel is CH1. In the case of ~ CH6, 2.475 GHz (second frequency) is used. As described above, the use frequency switching unit 34 selects the use frequency of the microwave M based on the frequency CN information from the wireless information acquisition unit 61 (see S13 in FIG. 2).

  FIG. 5 is a diagram illustrating an example of the microwave Doppler shift signal Ma.

  The microwave M easily passes through walls and ceilings, but is reflected by the subject 10. Further, since the Doppler shift corresponding to the body movement of the subject 10 and the movement of the muscle (breathing muscle) accompanying the breathing occurs in the microwave M reflected by the subject 10, the microwave Doppler shift signal Ma is obtained. It is possible to detect the number of body movements and the respiration rate of the subject 10. Respiratory muscle is a general term for muscles that expand and contract the rib cage when breathing. The posterior oblique muscle, rectus abdominis muscle, internal abdominal oblique muscle, external abdominal oblique muscle, lateral abdominal muscle and the like are included.

  5A shows a case where the distance between the microwave Doppler sensor 30 and the subject 10 is 2 m (short distance), and FIG. 5B shows a case where the distance between the microwave Doppler sensor 30 and the subject 10 is 5 m. The case (far distance) is shown. Although the amplitude intensity in FIG. 5B is lower than that in FIG. 5A, there is no difference in the tendency of the waveform change.

  Sections A to E shown in FIG. 5 show the breathing state of the subject 10. A section A shows a state in which the subject 10 is resting. Therefore, in the section A, the low-frequency microwave Doppler shift signal Ma is observed. Section B shows a state where the subject 10 is breathing quickly. Therefore, in the section B, the microwave Doppler shift signal Ma having an earlier period than the signal in the section A is observed. Section C shows a state where the subject 10 stops breathing. Accordingly, a flat microwave Doppler shift signal Ma is observed in section C. Section D shows a state in which the subject 10 returns to rest breathing after starting breathing again from a state where breathing has stopped. Therefore, in the section D, similarly to the section A, the low-frequency microwave Doppler shift signal Ma is observed. Section E shows a state in which body movement is applied during breathing. Therefore, in the section E, a microwave Doppler shift signal Ma in which a random component is added to a low-period component is observed.

  In the example shown in FIG. 5, the breathing is accelerated from the state of resting breathing, and the breathing is temporarily stopped. After that, the breathing is resumed and the body is moved. Thus, the safety of the subject 10 can be monitored by detecting the body motion number and the respiratory rate using the microwave Doppler shift signal Ma.

  FIG. 6 is a diagram for explaining the operation of the body motion number detection unit 51.

  FIG. 6A shows an example of the microwave digital data Md input to the time differentiating circuit 511 and an example of the microwave time change rate data Dd input to the threshold comparison circuit 512. FIG. 6B shows an example of the effective body motion signal Cd output from the threshold comparison circuit 512.

  As shown in FIG. 6A, when the time differential circuit 511 differentiates the microwave digital data Md at a sampling interval of 10 msec, a signal change rate appears. Therefore, the microwave time change rate data Dd obtained by differentiating the microwave digital data Md with respect to time has a waveform that increases or decreases a certain amplitude range around 0 (zero).

  In the threshold comparison circuit 512, “+ threshold” and “−threshold” as shown in FIG. 6A are set, and the microwave time change rate data Dd exceeds either “+ threshold” or “−threshold”. In this case, the effective body motion signal Cd is set to be output. The values of “+ threshold” and “−threshold” are determined in advance based on experimental results and the like, and it is determined that there is body movement if there is a movement that causes a change rate that is equal to or greater than the threshold.

  Next, the body motion counting circuit 513 generates a unit time based on the effective body motion signal Cd as shown in FIG. 6B and the second time signal T2 (pulse signal having a cycle of 30 seconds) from the time measuring unit 22. The number of body movements every time (every 30 seconds) is counted and output as the number of body movements Td (see S16 in FIG. 2).

  FIG. 7 is a diagram for explaining the operation of the respiration rate detection unit 52.

  FIG. 7A shows the microwave digital data Md1 and the frequency distribution data Fs obtained by processing the microwave digital data Md1 by the FFT circuit 512 when the subject 10 has no body movement. 7B shows the microwave digital data Md2 and the frequency distribution data Fs2 obtained by processing the microwave digital data Md2 by the FFT circuit 512 when the subject 10 has body movement. Further, FIG. 7C is a diagram illustrating an example of the fundamental wave data Rf output from the fundamental wave detection circuit 522.

  The respiratory waveform is not a simple sine wave, but includes individual harmonics, and if body motion is included, detection of each waveform becomes more difficult. Therefore, the respiration rate detection unit 52 employs a method in which real waveforms are collected at regular intervals, subjected to FTT processing, and decomposed into Fourier spectra for each frequency to detect the respiration rate.

  The fundamental wave detection circuit 522 selects a frequency distribution in a predetermined range related to respiration from the frequency distribution data Fs, and uses the frequency distribution including the frequency P having the highest intensity (peak) as the fundamental wave data Rf. . In FIG. 7A, the frequency distribution indicated as section R in the frequency distribution data Fs1 is defined as fundamental wave data Rf. Two frequencies R1 defining this section are 0.2 Hz, and R2 is 0.5 Hz. In addition, R1 and R2 are not necessarily limited to said value, A good value can be used suitably. In the case of FIG. 7A, since there is no frequency component in the section T described later, the frequency distribution data Fs1 is output as it is to the respiration counting circuit 523 as the fundamental wave data Rf.

  Since the biological reaction has normal distribution, if the component P is sequentially read out from the frequency R1 side in the section R and the frequency P having the highest peak can be selected, it can be predicted with high probability that it is the fundamental wave of respiration. Therefore, the frequency having the highest peak in a single shot is not regarded as the frequency P, and the frequency P that satisfies the condition that it is in an upward trend twice consecutively and is equal to or higher than a predetermined threshold to be distinguished from noise. Thus, the fundamental wave data Rf can be selected with higher accuracy.

  Further, in the fundamental wave detection circuit 522, as shown in FIG. 7B, the data (data shown in FIG. 7C) obtained by removing the frequency distribution in the section T from the calculated frequency distribution data Fs2 is fundamental. The wave data Rf is output to the respiration counting circuit 523. The reason why the section T shown in FIG. 7B is removed is that the frequency component in the section is a component related to body movement. R3 defining the section T is 0.5 Hz, and R4 is 5.0 Hz. R3 and R4 are derived from experimental results, but are not limited to the above values, and good values can be used as appropriate.

  Usually, the frequency distribution related to body movement is larger than the frequency distribution related to respiration. Therefore, R3 needs to be larger than R2. Further, since there is no clear periodicity in the body motion, the body motion does not appear as a clear frequency component in the frequency distribution data Fs subjected to the FFT processing. Therefore, in the fundamental wave detection circuit 522, the body motion component is removed from the respiratory component by defining the frequency range of the body motion as the section T.

  The respiration counting circuit 523 calculates the respiration rate Rr per unit time (1 minute) by multiplying the peak frequency P of the fundamental wave data Rf detected by the fundamental wave detection circuit 522 by 60 (see S17 in FIG. 2). ). For example, if the peak frequency P is 1 Hz, the respiration rate Rr per minute is 60 times.

  FIG. 8 is a diagram for explaining the safety pattern As and the like generated by the safety determination unit 92.

  FIG. 8A is a diagram illustrating an example of the safety pattern As generated by the safety determination unit 92. FIG. 8B is a diagram showing an indication that the notification unit 100 makes a notification based on the safety pattern As shown in FIG.

In determining the safety pattern As, an example of criteria for determining the number of body movements Td is shown below.
When the number of body movements Td <= 10: “No body movement”
500 => Number of body movements Td> 10: “There is body movement”
When the number of body movements Td> 500: “Body movement abnormality”

Similarly, an example of criteria for determining the respiratory rate Rr is shown below.
30 => respiration rate Rr> 0: “With respiration”
Respiration rate Rr> 30: “Respiratory abnormality”
Respiration rate = 0: “No breath detected”

  The safety patterns “A” to “E” included in the safety pattern As are shown below. The criteria for determining the number of body movements Td, the criteria for determining the respiratory rate Rr, and the corresponding criteria for the safety patterns “A” to “E” are all examples, including the number of times and the setting of the predetermined time. It is not limited.

  Safety pattern “A”: Applicable when “abnormal body movement” continues for 10 minutes or more in the daytime (AM6 to PM9). In the bedtime period (PM10 to AM6), it is assumed that “abnormal body movement” continues for 5 minutes or more. The safety pattern “A” is a pattern for determining that it is abnormal for an elderly person or the like to continue intense exercise in a room for a certain period of time.

  Safety pattern “B”: Applicable when “abnormal breathing” continues for 10 minutes or more in the daytime (AM6 to PM9). In the bedtime period (PM10 to AM6), “abnormal breathing” corresponds to a case in which 3 or more minutes continue. The safety pattern “B” is a pattern for determining that it is abnormal for an elderly person or the like to normally keep breathing early in a room for a certain period of time.

  Safety pattern “C”: Applicable when “with body movement” continues for 60 minutes or more in the daytime (AM6 to PM9). In the bedtime period (PM10 to AM6), “with body movement” corresponds to a case where 10 minutes or more continue. The safety pattern “C” is a pattern for determining that it is abnormal for an elderly person or the like to keep moving a body for a certain period of time in a room.

  Safety pattern “D”: “no body movement” and “with breathing” or “breathing abnormality” for 5 minutes or more in the daytime (AM6 to PM9), “no body movement” and “no breathing detected” Applicable when the duration is 5 minutes or more. In the bedtime (PM10 to AM6), “no body movement” and “with breathing” or “abnormal breathing” continue for 3 minutes or more, and “no body movement” and “no breathing detection” take 3 minutes. Applicable when consecutive. The safety pattern “D” is a pattern for determining the abnormality (sudden breathing stop) of the subject 10 without being confused with the case where the subject 10 has moved outside the room. The above judgment is based on the recognition that when the subject 10 moves out of the room and becomes “respiration not detected”, “with body motion” or “body motion abnormality” should be detected. ing.

  Safety pattern “E”: During the day (AM6 to PM9), after “with body movement” or “abnormal body movement”, “no body movement” and “breathing” continuously for 60 minutes from within 2 minutes. Applicable when "Not detected". In the bedtime period (PM10 to AM6), after “with body movement” or “body movement abnormality”, “no body movement” and “no breathing detection” continuously for 20 minutes from within 2 minutes. Applicable if The safety pattern “E” is a pattern that is determined to be abnormal when the subject 10 does not return to the room within a predetermined time after moving to the outside of the room.

  As shown in FIG. 8A, the notification determination unit 102 of the notification unit 100 sets safety points for the safety patterns “A” to “E”, and accumulates the points as shown in FIG. 8B. Accordingly, a safety level is set, and a notification operation is performed so that the administrator takes a response corresponding to each safety level (low to high).

  When the safety level is “low”, for example, as shown in FIG. 9, a predetermined message is displayed on the screen of the notification terminal 110, and the subject 10 himself / herself is prompted to confirm. When the safety level is “medium”, for example, an e-mail is transmitted to the communication terminal 120 possessed by the administrator, and the subject 10 is directly urged to confirm the conversation by telephone. When the safety level is “high”, an e-mail is transmitted to the communication terminal 120 possessed by the administrator, and, for example, the person is urged to visit the subject 10 directly for confirmation.

  FIG. 9 is an external view showing an example of the notification terminal 110.

  The notification terminal 110 includes a display unit 111, a speaker 112, and operation switches 113 and 114, and is configured to receive a report from the safety server 90 and notify the report content.

  For example, in FIG. 8B, when the notification determination unit 102 of the safety server 90 determines that the safety level is “low”, the notification terminal 110 receives a notification from the communication unit 103 and displays the notification on the display unit 111. It is possible to control the display as shown in FIG.

  Further, when the subject 10 does not operate the operation switch 113 or 114 within a predetermined time in response to the question “Is there any abnormality?”, The communication terminal 120 possessed by the administrator of the safety monitoring system 1 is predetermined. You can also send an email to alert the administrator.

  In the safety monitoring system 1 including the safety monitoring device 20 described above, the wireless LAN belonging to the same frequency band and the microwave can be used without causing interference, so the installation location of the safety monitoring device 20 including the microwave Doppler sensor 30 is installed. It becomes possible to increase the degree of freedom of safety monitoring without choosing.

  In the above description, the example using the 2.4 GHz communication band is shown, but the communication band is not limited to this, and the present invention can be applied to other communication bands. The important point is to prevent radio waves for wireless LAN existing in the same communication frequency band from interfering with microwaves for detecting body movement and / or respiration rate of the subject.

  In the safety monitoring system 1 described above, the safety monitoring device 20 detects the number of body movements and the number of breaths, which are safety information, transmits it to the safety server 90, and determines how to report on the safety server 90 side. Like to do. However, the safety monitoring device 20 may determine how to make a report, and may send only the information instructing the report to the safety server 90, or report directly to the notification terminal 110 or the communication terminal 120. May be. Further, the safety monitoring device 20 does not detect the number of body movements and the respiration rate, but transmits only the microwave Doppler shift signal Ma as the safety information to the safety server 90, and the number of body movements and the respiration on the safety server 90 side. You may make it judge how to report, after detecting a number.

DESCRIPTION OF SYMBOLS 1 Safety monitoring system 20 Safety monitoring apparatus 30 Microwave Doppler sensor 34 Use frequency switching part 40 Signal processing part 50 Detection part 51 Body motion number detection part 52 Respiration rate detection part 60 Wireless transmission part 61 Wireless information acquisition part 70 Wireless reception part 80 Network 90 Safety server 110 Notification terminal 120 Communication terminal

Claims (5)

A microwave Doppler sensor,
A frequency switching unit for switching the frequency of the microwave used in the microwave Doppler sensor;
A safety information acquisition unit that acquires safety information of the subject by irradiating the subject with the microwave and receiving a reflected wave;
A wireless transmission unit that performs wireless communication with an access point and transmits the safety information;
A detection unit that detects a frequency channel for the wireless transmission unit to perform wireless communication with an access point; and
The frequency switching unit switches the frequency of the microwave based on the frequency channel detected by the detection unit so that interference with radio communication by the radio transmission unit does not occur.
A safety monitoring device characterized by that. A noise filter for removing noise;
The detection unit further detects a transfer rate when the wireless transmission unit performs wireless communication with an access point,
The safety monitoring device according to claim 2, wherein a noise removal band by the noise filter is set based on the transfer rate.   The safety monitoring device according to claim 1, wherein the detection unit receives a beacon output from an access point and detects the frequency channel.   The safety monitoring device according to any one of claims 1 to 3, wherein the safety information is a body motion number or a respiratory rate of the subject.   The safety monitoring device according to any one of claims 1 to 3, wherein the safety information is a microwave Doppler shift signal from the microwave Doppler sensor.

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