JP2020062291A - Biological information detection device and biological information detection method - Google Patents

Abstract

To provide a simple-structure biological information detection device and biological information detection method capable of detecting a wide range of information including biological information, changes in position, and movements of a target that needs to be watched.SOLUTION: Provided is a biological information measurement device, comprising: a microwave transmission unit for sending a microwave of a predetermined frequency to space in such a manner that the microwave passes near a measurement target; a microwave receiving unit for receiving a passing microwave that has been transmitted from the microwave transmission unit and propagated in the vicinity of the measurement target; a demodulation unit for demodulating a passing wave reception signal, which is a signal of the received passing microwave, using a microwave signal from the microwave transmission unit; and an analysis unit for chronologically monitoring a state of the measurement target by measuring the amplitude and phase of the demodulated signal output from the demodulation unit.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a biological information detection device and a biological information detection method.

  When taking care of patients, families, etc. in hospitals, nursing homes, homes, etc., watching over those persons occupies an important position. By appropriately watching, it is possible to take timely measures if there is a change in the condition or situation of the patient, etc., and it is possible to prevent the patient, etc. from encountering an accident such as a fall.

  However, on the other hand, especially when there are many people to be watched over, such as hospitals and nursing homes, it is necessary for people such as nurses, caregivers, and family members to continue while patroling the beds, living rooms, etc. In order to grasp the situation of each person to be watched, it is necessary for the person in charge to work with tension. In Japan, where the birthrate is declining and the population is aging rapidly, it is difficult to secure the necessary labor force in such a working environment.

  Therefore, various technical proposals have been made in order to realize such labor saving in watching. For example, Patent Document 1 describes a sleep stage determination device including a detection unit that detects body movement, respiration, and pulse waves using a microwave Doppler radar. Further, Patent Document 2 describes a breathing determination device that irradiates a subject with a microwave and determines the breathing state of the subject based on a reflected wave reflected from the subject.

JP, 2016-107095, A Japanese Patent No. 5777817

  In each of Patent Documents 1 and 2, by irradiating a target with microwaves and measuring the reflected wave, biological information such as the respiratory state of the target or the motion of the target is detected in a non-contact manner. The configuration is adopted. As a result, it is considered that a nurse or the like who takes care of the watching target does not need to visit the bed or the like to be checked and visually check the condition.

  However, in the configuration that uses the reflected wave of the microwave irradiation, in order to properly receive the reflected wave, it is necessary to irradiate the microwave in a spot on a relatively narrow area of the watching target, so It may be difficult to properly receive the reflected wave when changing or moving. In addition, generally used microwave transmitters on the order of 10 GHz require a high precision in circuit design and parts used for stable operation, and thus it is difficult to suppress product cost.

  The present invention has been made to solve the above problems and other problems, and has a simple configuration that can detect a wide range of biometric information, posture changes, movements, etc. of a watching target and a biometric information detection. The purpose is to provide a method.

  In order to achieve the above and other objects, the biological information detection device according to an aspect of the present invention, a microwave transmission unit that sends the microwave of a predetermined frequency to the space so as to pass near the measurement target, A microwave receiving unit that receives a passing wave that is a microwave that has been transmitted from the microwave transmitting unit and has propagated in the vicinity of the measurement target, and a passing wave reception signal that is a signal of the received passing wave, the microwave receiving unit A demodulation unit that demodulates using the microwave signal from the wave transmission unit, and an analysis unit that monitors the state of the measurement target by measuring the amplitude and phase of the demodulation signal output from the demodulation unit over time. Equipped with.

  The analysis unit monitors the amplitude and phase of the passing wave reception signal, and when it is determined that the fluctuation of the amplitude does not exceed a predetermined range for a predetermined time, it is determined that an abnormality has occurred in the measurement target. Good.

  The analysis unit further analyzes the respiratory state of the measurement target based on the passing wave reception signal, and the predetermined range provides a determination criterion for determining whether the amplitude is abnormal in the respiratory state of the measurement target. can do.

  Further, the analysis unit continuously monitors whether the fluctuation range of the amplitude exceeds a predetermined threshold value, and when determining that the fluctuation range exceeds the predetermined threshold value, the measurement target exists around the propagation path of the passing wave. It can be determined not to.

  A biological information measuring method corresponding to the biological information measuring device also constitutes an aspect of the present invention.

  According to one aspect of the present invention, it is possible to provide a biometric information detection device and a biometric information detection method that are capable of widely detecting biometric information, posture changes, movements, and the like of a watching target with a simple configuration.

FIG. 1 is a diagram showing a configuration example of a respiratory measurement system 1 according to an embodiment of the present invention. FIG. 2 is a schematic diagram showing a configuration example of the respiratory measurement device 100 according to the present embodiment. FIG. 3 is a diagram illustrating a configuration example of the analysis unit 160 included in the respiratory measurement device 100. FIG. 4 is a flowchart showing an example of data processing executed by the analysis unit 160. FIG. 5 is a schematic diagram illustrating the principle of analysis of received microwaves performed by the analysis unit 160. FIG. 6 is a schematic diagram illustrating the principle of respiratory state analysis by the received microwaves performed by the analysis unit 160.

  Hereinafter, the present invention will be described with reference to the drawings in accordance with an embodiment thereof.

Configuration of Respiration Measurement System First, a configuration example of the respiration measurement system according to the present embodiment will be described. FIG. 1 schematically shows a configuration example of the respiration measurement system 1 according to the present embodiment, and FIG. 2 schematically shows a configuration example of the respiration measurement device 100 included in the respiration measurement system 1 of FIG.

  The respiration measurement system 1 according to the present embodiment includes a respiration measurement device 100, and a transmission antenna TA and a reception antenna RA connected to the respiration measurement device 100. The respiration measurement device 100 is an electric / electronic circuit unit that provides the main functions of the present system 1, and also includes a computer having a processor and a memory. A specific configuration example of the respiratory measurement device 100 will be described later.

  The transmission antenna TA is an antenna for transmitting a microwave having a predetermined frequency and a predetermined output, which is generated in the respiratory measurement device 100. As the transmission antenna TA, a single type antenna, a Yagi type antenna, a horn antenna, a parabolic antenna, a planar antenna, and other types of antennas suitable for microwave transmission can be used. The reception antenna RA is an antenna for receiving the microwave transmitted from the transmission antenna TA, and like the transmission antenna TA, an antenna of an appropriate format suitable for microwave reception can be used.

  The respiratory measurement system 1 of FIG. 1 is provided to watch over a person H lying on the bed B as a target person and continuously monitor the state. One feature of the present system 1 is that, in order to monitor the state of the person H, it is not a reflected wave of a microwave but is transmitted from a transmission antenna TA and propagated in the vicinity of an object (in this case, the person H) to be received. That is, microwaves received by the antenna RA (hereinafter referred to as “passing waves”) are used. In FIG. 1, this passing wave is schematically shown by a broken line arrow and denoted by reference numeral RW. The present system 1 can obtain data on whether the person H is on the bed B and the breathing condition of the person H by continuously monitoring and analyzing the passing wave received by the receiving antenna RA. it can. The positional relationship between the transmitting antenna TA and the receiving antenna RA may be set so that the passing wave passes near the person H lying on the bed B. In this respect, the positional relationship among the person H, the transmitting antenna TA, and the receiving antenna RA does not require strictness. Further, although the present system 1 is configured to be able to detect the respiratory condition as the biological information of the person H, other biological information such as the heartbeat can be obtained by adjusting the analysis processing of the received passing wave, which will be described later. It can also be configured to measure. In addition, the measurement target is not limited to the person H, and may be other organisms such as dogs and cats.

Configuration of Respiration Measurement Device Next, the respiration measurement device 100 included in the respiration measurement system 1 of FIG. 1 will be described. The respiratory measurement device 100 performs the functions of generation, transmission, reception of a microwave (passing wave) and analysis of the received passing wave. As shown in FIG. 2, the respiration measurement device 100 includes a microwave oscillating unit 110, a distributor 120, a transmission amplification unit 130, a reception amplification unit 140, a quadrature demodulation circuit 150 (demodulation unit), an analysis unit 160, a communication unit 170, And a power supply unit 180. The microwave oscillation unit 110, the distributor 120, and the transmission amplification unit 130 can be regarded as a microwave transmission unit, and the reception amplification unit 140 can be regarded as a microwave reception unit.

  The microwave oscillating unit 110 is an oscillating circuit for generating a microwave having a predetermined frequency, and includes an oscillator of an appropriate type such as a voltage controlled oscillator (VCO). In the present system 1, microwaves having a sine waveform with a frequency of 2.4 GHz are used, but microwaves with a lower frequency (100 MHz order) can also be used. The reason why the microwave having such a relatively low frequency can be used is that the high resolution is not required as in the case of the method of detecting the reflected wave. By using a microwave having a relatively low frequency, the accuracy required for the oscillator circuit can be suppressed and the manufacturing cost can be reduced.

  The microwave signal (sine wave signal) generated by the microwave oscillation unit 110 is input to the distributor 120, distributed to the transmission amplification unit 130 and the quadrature demodulation circuit 150, and output. As the distributor 120, a high frequency distributor having a distribution characteristic according to the frequency used can be used. The signal output to the quadrature demodulation circuit 150 will be described later.

  One of the outputs from the distributor 120 is input to the transmission amplification section 130. In the transmission amplification unit 130, the microwave signal from the distributor 120 is power-amplified, and the amplified microwave signal is transmitted from the transmission antenna TA to the space. The above is the configuration of the respiratory measurement device 100 on the microwave transmission side.

  On the other hand, the passing wave which is the microwave propagating in the space is received by the reception antenna RA and input to the reception amplification section 140. The signal of the passing wave is power-amplified by the reception amplification section 140 and input to the quadrature demodulation circuit 150. The power-amplified passing wave signal is called a passing wave reception signal. As described above, one output signal of the distributor 120 is input to the quadrature demodulation circuit 150.

  In the quadrature demodulation circuit 150, the passing wave reception signal is multiplied by the microwave transmission signal input from the demultiplexer 120 to perform quadrature demodulation processing, and an in-phase component I signal and a quadrature component Q signal are generated. Extract. Since the transmission signal itself from the distributor 120 is used for this quadrature demodulation processing, the reception signal and the transmission signal can be accurately synchronized, and as a result, the I signal and the Q signal can be obtained accurately. it can. Not limited to the quadrature demodulation circuit 150, the amplitude can be extracted by performing envelope detection of the passing wave reception signal.

  The I signal and the Q signal output from the quadrature demodulation circuit 150 in FIG. 2 are input to the analysis unit 160, and the amplitude fluctuation of the received signal is continuously monitored. FIG. 3 shows a configuration example of the analysis unit 160. The analysis unit 160 of this embodiment is configured as a computer including a processor 161 such as a CPU and a main storage device 162 that is a storage device such as a ROM and a RAM. An analysis program 1621 and analysis data 1622 are stored in the main memory 162. The analysis program 1621 realizes the function of the analysis unit 160 by being executed by the processor 161. The analysis data 1622 includes numerical data used when the analysis program 1621 is executed. The data processing of the analysis program 1621 will be described later.

  The auxiliary storage device 163 is a storage device such as a hard disk drive, a semiconductor drive, or a memory card, and can be used to store data such as an analysis processing execution result by the analysis program 1621. The input / output unit 164 includes an input device such as a touch panel and a keypad, a data input / output device such as an output device such as a liquid crystal display and a printer. The configuration of the analysis unit 160 is not limited to the example illustrated in FIG. 3, and may be configured by a hardware logic circuit or the like, for example.

  Returning to FIG. 3, the analysis result data from the analysis unit 160 is input to the communication unit 170. The communication unit 170 includes an interface that controls communication with a communication network such as a LAN or the Internet, and includes hardware such as a network interface card (NIC). The communication unit 170 can perform data communication with an external device such as a mobile terminal or a server computer, and thereby send analysis result data or the like to the external device. The power supply unit 180 is a power conversion circuit including an ACDC converter, a transformer, and the like, and has a function of receiving power supply from a commercial AC power supply, performing necessary power conversion, and then supplying power to each unit of the respiratory measurement device 100. Have.

Data Processing by Analysis Unit Next, data processing executed by the analysis unit 160 of the respiratory measurement device 100 will be described. FIG. 4 shows a flowchart showing an example of data processing by the analysis unit 160. The analysis unit 160 uses the I signal and the Q signal output from the quadrature demodulation circuit 150 to monitor the amplitude fluctuation of the passing wave reception signal over time. FIG. 5 schematically shows the vector of the passing wave reception signal on the IQ plane. The microwave (passing wave) that is transmitted from the transmitting antenna TA and propagates in the vicinity of the person H to be measured is partially affected by the body of the person H such as scattering and deflection, and its amplitude and phase change. For example, as schematically shown in FIG. 5, when the person H is not on the bed B, the vector on the IQ plane is V1, and its magnitude represents the received signal strength. On the other hand, when the person H is on the bed B, the magnitude and direction of the vector on the IQ plane change to V2, and the received signal strength decreases due to the influence of the person H. By determining the magnitude of the vector on the IQ plane by an appropriate threshold value that can be set through experiments or the like, the analysis unit 160 can determine whether or not the person H is on the bed B.

  Specifically, in FIG. 4, when the processing is started in S400, the analysis unit 160 monitors the I signal and the Q signal of the passing wave reception signal input from the quadrature demodulation circuit 150 (S401), and on the IQ plane. It is determined whether the magnitude of the vector is equal to or larger than a predetermined value (S402). When it is determined that the magnitude of the vector is equal to or larger than the predetermined value (S402, Yes), the analysis unit 160 determines that the person H who is the measurement target is not on the bed B (is in a bed) (S403). , Return to the I signal / Q signal monitoring step of S401. Note that in S403, the analysis unit 160 may be configured to display the determination result via the input / output unit 164 or send the determination result to an external device via the communication unit 170. The determination threshold used in step S402 may be stored as the analysis data 1622.

  When it is determined in S402 that the size of the vector is less than the predetermined value (S402, No), the analysis unit 160 determines that the person H who is the measurement target is on the bed B (being in bed) ( S404). Similar to S403, in S404, the analysis unit 160 may be configured to display the determination result via the input / output unit 164 or send the determination result to an external device via the communication unit 170.

  When it is determined that the person H is on the bed B, the analysis unit 160 further monitors the change in the magnitude of the vector over time based on the I signal and the Q signal (S405). FIG. 6 schematically shows how the magnitude of the vector (amplitude of the received signal of the passing wave) changes when the person H is determined to be in bed. When the person H is in bed, the magnitude of the vector representing the amplitude and phase of the received signal of the passing wave does not differ as much as when bed and bed. Instead, it is possible to detect a small temporal change in the magnitude of the vector by reflecting the displacement of the chest that accompanies the breathing of the human H. Therefore, by appropriately setting the determination range of the temporal change, It is possible to determine the state. In the schematic diagram of FIG. 6, the horizontal axis represents time t, and the vertical axis represents the amplitude A (vector magnitude on the IQ plane) of the passing wave reception signal. Is shown as. In the example of FIG. 6, the analysis unit 160 determines that the person H is breathing normally when the amplitude of the received signal fluctuates beyond the range of ΔA, and a small fluctuation within the range of ΔA. When it is determined that the period of staying at 3 has continued for the time ΔT, the determination logic for determining that the breathing state of the person H is modulated is adopted. Of course, other methods may be applied to the determination of the breathing state.

  Returning to the flowchart of FIG. 4, when it is determined that the person H is in bed, the analysis unit 160 further determines whether the magnitude of the vector representing the amplitude and the phase of the received signal of the passing wave has a predetermined change over time. A determination is made (S406). When it is determined that there is a predetermined change over time (S406, Yes), the analysis unit 160 determines that there is no abnormality in the breathing state of the person H and ends the analysis processing (S407, S408). In S407, the analysis unit 160 may be configured to display the determination result via the input / output unit 164 or send the determination result to an external device via the communication unit 170.

  When it is determined that the magnitude of the vector has not changed for a predetermined time (S406, No), the analysis unit 160 further determines whether the state without the change continued for a predetermined time (S409). When it is determined that the state without time change has not continued for the predetermined time (S409, No), the analysis unit 160 repeats the determination step of S409, and when it is determined that the state without time change has continued for the predetermined time (S409, Yes), the analysis unit 160 determines that the breathing state of the person H is abnormal (S410), outputs a message to that effect, and ends the processing (S411, S408).

  Through the above-described data processing of the analysis unit 160, whether or not the person H to be measured is on the bed B, and if on the bed B, whether or not the breathing state is normal is determined using the present system 1. It can be monitored continuously. The monitoring result can be displayed on the input / output unit of the respiratory measurement device 100 or output to an external device such as a mobile terminal. Therefore, if this system 1 is applied to watch over inpatients or residents of nursing homes, nurses and caregivers do not have to directly visually check the conditions of inpatients, leaving the bed, going to bed, and breathing. The state of can be continuously monitored, and the labor can be reduced.

  In the above embodiments, the present invention has been described by exemplifying the case where the present invention is implemented as a respiratory measurement system. In the present invention, not only breath measurement, but also biological information such as heartbeat, blood flow, convulsion of the extremities, or information such as posture change when the watching target is in bed, without going to the watching target. It can be acquired over time. At this time, regarding the detection of the biological information and the posture change, how the influence of the passing wave appears as the amplitude change of the passing wave reception signal in advance is understood through a test, and the result is used as a judgment algorithm or a judgment threshold value. It can be appropriately realized by incorporating it into an analysis program.

  The technical scope of the present invention is not limited to the above embodiment, and other modifications, applications, etc. are also included within the scope of the matters described in the claims.

1 Respiratory measurement system 100 Respiratory measurement device 110 Microwave oscillating unit 120 Distributor 130 Transmission amplifying unit 140 Reception amplifying unit 150 Quadrature demodulation circuit 160 Analysis unit 170 Communication unit 180 Power supply unit 1621 Analysis program TA Transmission antenna RA Reception antenna

Claims (5)

A microwave transmission unit that sends a microwave of a predetermined frequency to the space so as to pass near the measurement target,
A microwave receiving unit that receives a passing wave that is a microwave that has been transmitted from the microwave transmitting unit and has propagated in the vicinity of the measurement target,
A demodulation unit that demodulates a passing wave reception signal that is a signal of the received passing wave using the microwave signal from the microwave transmission unit;
A biological information measuring device, comprising: an analysis unit that monitors the state of the measurement target by measuring the amplitude and phase of the demodulated signal output from the demodulation unit over time.   The analysis unit monitors the amplitude and phase of the received signal of the passing wave, and determines that an abnormality occurs in the measurement target when it is determined that the fluctuation of the amplitude does not exceed a predetermined range for a predetermined time, Item 2. The biological information measurement device according to item 1.   The analysis unit analyzes a respiratory state of a measurement target based on the passing wave reception signal, and the predetermined range provides a determination standard for determining whether the amplitude is abnormal in the respiratory state of the measurement target, Item 2. The biological information measurement device according to item 2.   The analysis unit continuously monitors whether the fluctuation range of the amplitude exceeds a predetermined threshold value, and when it is determined that the fluctuation range exceeds the predetermined threshold value, the measurement target does not exist around the propagation path of the passing wave. The biological information measuring device according to claim 1, wherein the determination is performed. A microwave of a predetermined frequency is sent to the space so that it passes near the object to be measured,
Receiving a passing wave that is a microwave transmitted to the space and propagating near the measurement target,
A passing wave reception signal which is a signal of the received passing wave is demodulated using the microwave signal sent to space,
By measuring the amplitude and phase of the demodulated signal over time, monitor the state of the measurement target,
Biological information measurement method.

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