JP2007097821A - Behavior monitoring system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To precisely detect a posture of a subject directly from a measurement value of an acceleration sensor without using a separate means and acquiring initial value information with the possibility to increase accumulated errors. <P>SOLUTION: A behavior monitoring system constituted to communicate a sensor unit 1 mounted on the subject with a center device 2 to monitor behavior of the subject is equipped with the sensor unit 1 having the acceleration sensor and a communication means transmitting acceleration data measured by the acceleration sensor to the center device as sensing signals and the center device 2 having a period and amplitude analyzing part 24b for receiving the sensing signals sent from the communication means in a time-series manner and analyzing a period and an amplitude of the time-series acceleration data contained in the sensing signals and a behavior status determining part 24c for determining a behavior state of the subject based on the acceleration data period and the acceleration data amplitude acquired by the analysis. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a system for monitoring the behavior of a subject using output data of an acceleration sensor, for example, and in particular, a behavior monitoring system for monitoring various behaviors such as walking, running slowly, running, etc. based on the output of an acceleration sensor. It is about.

  Conventionally, in order to grasp the behavior of a patient who is performing rehabilitation in a hospital or a nursing home, a sensor is attached to a predetermined part of the patient's body surface, and a predetermined calculation is performed on an output signal from the sensor, An apparatus for determining the posture of a subject based on the calculation result is known.

For example, in Patent Document 1, a three-axis acceleration sensor is attached to each of the subject's chest, arm, and foot, and the position of the attached acceleration sensor is measured, for example, the posture of the subject, for example, the standing state, Techniques for detecting each state such as a sitting state, a walking state, and a lying state are disclosed.
JP 2005-50290 A

  However, normally, the position where the acceleration sensor is mounted can be obtained by performing double integration with respect to the time of the measurement value of the acceleration sensor. In this case, however, an initial value of speed and an initial value of position are required. Therefore, it is necessary to obtain the initial value information or to store and use the position information and speed information obtained from the start of measurement as the initial value information. In the former case, another means for obtaining the initial value is required, which further complicates the detection of the position information. In the latter case, if the measurement time is long, the accumulated error increases and it is difficult to detect the accurate position information. .

  The object of the present invention is to directly and highly accurately determine the posture of the subject from the measured value of the acceleration sensor without requiring the use of another means or obtaining initial value information that may increase cumulative error. It is to detect with.

  In order to achieve the above object, according to a first aspect of the present invention, there is provided a behavior monitoring system in which a sensor unit attached to a subject and a center device are configured to be communicable and monitor behavior related to the subject. A sensor unit having an acceleration sensor and communication means for transmitting the acceleration data measured by the acceleration sensor as a sensing signal to the center device; and receiving the sensing signal sent from the communication means in time series. A period / amplitude analysis unit that analyzes the period and amplitude of time-series acceleration data included in the signal, and an action state that determines the action state of the subject based on the acceleration data period and acceleration data amplitude obtained by this analysis There is provided an action monitoring system comprising a center device having a determination unit.

  According to a second aspect of the present invention, there is provided a behavior monitoring system in which a sensor unit attached to a subject and a center device are configured to be communicable and monitor behaviors related to the subject, the acceleration sensor and the acceleration sensor. A sensor unit having a storage unit for storing acceleration data measured by the step, and a period / amplitude analysis unit for reading the acceleration data from the storage unit in time series and analyzing the period / amplitude of the time series acceleration data; There is provided a behavior monitoring system comprising: a center device having a behavior state determination unit that determines a behavior state of a subject based on an acceleration data period and acceleration data amplitude obtained by the analysis. The

  In a third aspect of the present invention, in the first or second aspect, the behavior state determination unit refers to a table that defines a predetermined region, and based on the region to which the converted data belongs, There is provided an action monitoring system further characterized by determining a state.

  According to the present invention, the posture of the subject is detected directly and with high accuracy from the measurement value of the acceleration sensor without the need to obtain initial value information that may be used such as using another means or increasing the accumulated error. An action monitoring system can be provided.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

  FIG. 1 is a conceptual diagram of an action monitoring system according to an embodiment of the present invention.

  In the behavior monitoring system according to this embodiment, the sensor unit 1 and the center apparatus 2 attached to the chest of the subject to be monitored and the center device 2 are connected and configured to be capable of communication via a wireless network, for example. ing. Of course, the sensor unit 1 and the center device 2 may be configured to communicate with each other via a relay unit (not shown).

  The center device 2 shown in FIG. 1 includes an antenna unit 21, a signal distribution unit 22, a reception unit 23, a sensor data collection processing unit 24, a sensor control unit 25, and a transmission unit 26.

  The sensor data collection processing unit 24 includes an acceleration data storage unit 24a, an acceleration data cycle / amplitude analysis unit (hereinafter simply referred to as a “cycle / amplitude analysis unit”) 24b, and an action state determination unit 24c.

  In such a configuration, the antenna unit 21 has a transmission antenna function for transmitting a control signal from the sensor control unit 25 and a reception antenna function for receiving a sensing signal from the sensor unit 1. Switching between these functions is performed by a signal distribution unit 22 including a circulator connected to the antenna unit 21. After receiving the wireless signal transmitted from the sensor unit 1 via the wireless network or the antenna unit 21, the receiving unit 23 demodulates the wireless signal and transmits the sensing signal obtained by this demodulation to the sensor data collection processing unit 24. Output.

  The transmission unit 26 modulates the control signal output from the sensor control unit 25, converts it to a radio signal, and transmits the radio signal from the antenna unit 21 to the sensor unit 1 via the radio network. The sensor control unit 25 includes, for example, a CPU (Central Processing Unit) and a DSP (Digital Signal Processor), and outputs a control signal including a command related to the start of sensing by the sensor unit 1 and a sensing cycle.

  The sensor data collection processing unit 24 is a part that determines the behavior, that is, the state of the subject from the received sensing signal. In the present embodiment, since the purpose is to monitor the behavior by detecting the state of the subject, the center apparatus 2 continuously receives the sensing signal from the sensor unit 1. When a sensing signal as acceleration data is received from the receiving unit 23, the sensor data collection processing unit 24 temporarily stores the acceleration data in the acceleration data storage unit 24a. Next, the stored acceleration data is read as appropriate, and the period / amplitude analysis unit 24b performs the period / amplitude analysis. Based on the analysis result, the behavior state determination unit 24c determines the behavior state of the subject as will be described in detail later.

  On the other hand, as shown in FIG. 1, the sensor unit 1 attached to the object includes a sensor unit 11 including an acceleration sensor, a sensor drive control unit 12, a sensing signal transmission unit 13, an antenna unit 14, and a sensor drive signal reception. A unit 15 and a battery 16 are provided.

  Here, as shown in FIG. 2, the sensor drive signal receiving unit 15 may be deleted from the configuration shown in FIG. 1, and the sensor unit 3 may be driven independently. In this case, the sensor unit 3 includes a sensor unit 31, a sensor drive control unit 32, a sensing signal transmission unit 33, an antenna unit 34, and a battery 36. Control signals including commands related to the start of sensing and the sensing cycle are stored in the sensor drive control unit 32.

  Further, as shown in FIG. 3, the sensing signal transmission unit 13, the antenna unit 14, and the sensor drive signal reception unit 15 are deleted from the configuration shown in FIG. 1, and the sensor unit 2 is independent without communicating with the center device 2. You may make it operate | move. In this case, the sensor unit 4 includes a sensor unit 41, a sensor drive control unit 42, a sensing signal storage unit 43, and a battery 44.

  Hereinafter, in this embodiment, further explanation will be made on the assumption that the sensor unit 1 having the configuration as shown in FIG.

  FIG. 4 shows a detailed configuration of the sensor drive control unit 12 and the sensor unit 11 which are components of the sensor unit 11 and will be described. The sensor unit 11 includes an acceleration sensor 11a. The sensor drive control unit 12 includes a CPU (central control unit) 12a, an AD conversion unit 12b, a storage unit 12c, a server programming interface (SPI) 12d, and a clock signal generation unit 12e.

  In such a configuration, the clock signal generator 12e generates a clock signal having a predetermined period based on the clock control signal of the CPU 12a. The storage unit 12c stores programs executed by the CPU 12a, setting data, and the like. The CPU 12a controls the sensing signal transmitting unit 13 and the sensor driving signal receiving unit 15 including the acceleration sensor 11a of the sensor unit 11, and starts and ends the sensing and sensing cycle sent from the center device 2 described above. Etc. are stored in a memory (not shown).

  The CPU 12a generates a clock control signal based on the stored command and the setting data stored in the storage unit 12c, and outputs the clock control signal to the clock signal generation unit 12e. Further, the CPU 12a generates a signal related to sensing start and end and a sensing cycle as a drive signal based on the clock signal generated from the clock signal generator 12e. The AD converter 12b converts acceleration data from the acceleration sensor 11a driven by a control signal from the CPU 12a into a digital signal, and outputs it as a sensing signal from the CPU 12a via the SPI 12d. A standby signal is used as a drive signal supplied from the CPU 12a to the acceleration sensor 11a. The acceleration sensor 11a enters an operation state in which sensing is performed when the standby signal becomes “H” level, and enters a non-operation state, that is, a standby state with less power consumption when the signal becomes “L” level. The battery 16 is made of, for example, a button-type lithium battery, and supplies a DC voltage as drive power to the sensor unit 11, the sensor drive control unit 12, the sensing signal transmission unit 13, and the sensor drive signal reception unit 15.

  FIG. 5 shows a detailed configuration of the sensing signal transmission unit 13 and the sensor drive signal reception unit 15 which are components of the sensor unit 1 and will be described. The sensing signal transmission unit 13 includes an SPI 13a, a digital signal control unit 13b, a signal modulation unit 13c, a mixing unit 13d, a power amplification unit 13e, and a transmission / reception signal distribution unit 13f. The sensor drive signal receiving unit 15 includes an SPI 15a, a crystal oscillator 15b, a phase stabilization circuit 15c, a voltage controlled oscillator 15d, a low noise amplification unit 15e, a mixing unit 15f, a signal demodulation unit 15g, and a digital signal control unit 15h. ing.

  In such a configuration, the sensing signal transmission unit 13 takes in the sensing signal from the sensor drive control unit 12 to the digital signal control unit 13b via the SPI 13a, and performs digital modulation, for example, QPSK (Quadrature Phase Shift Keying) by the signal modulation unit 13c. ) Modulated and converted to a predetermined frequency mixed with the output of the voltage controlled transmitter 15d by the mixing unit 13d to create sensing data, the power of the sensing data is amplified by the power amplification unit 13e, and the transmission / reception signal distribution unit 13f Then, the signal is transmitted toward the center device 2 via the antenna unit 14.

  On the other hand, when the sensor drive signal receiving unit 15 receives the radio signal transmitted from the center device 2 by the antenna unit 14, the sensor driving signal receiving unit 15 distributes the signal by the transmission / reception signal distributing unit 13f, filters it by the low noise amplifying unit 15e, and then sends it to the mixing unit 15f. take in. The mixing unit 15f converts the radio signal to a predetermined frequency mixed with the output of the voltage controlled oscillator 15d, and then digitally demodulates the signal by the signal demodulation unit 15g. The control signal obtained by the digital demodulation is converted into a digital signal. It is supplied from the control unit 15h to the sensor drive control unit 12 via the SPI 15a.

  Hereinafter, characteristic portions of the behavior monitoring system according to the embodiment of the present invention will be described.

  In the behavior monitoring system according to the embodiment of the present invention, a sensor unit 1 including an acceleration sensor 11a that is a left / right sensor is attached to the body surface (for example, the chest) of a subject, and the body center of gravity is determined by how the subject walks. Each state is discriminated from the period and amplitude of the up and down movement of the movement. Here, “amplitude” is the amplitude of acceleration time change data, and “cycle” is the frequency of acceleration time change data.

  For example, as shown in FIG. 6A, when the subject is in a “stand still” state, the period of the left and right sensors is substantially zero and the amplitude is also substantially zero. As shown in FIG. 6B, when the subject is in the “walking” state, the cycle of the left and right sensors is determined by the walking stride, and the cycle varies depending on how to walk. In this case, the amplitude of the left and right sensors is smaller than the “slowly running” and “running” states described later. Further, as shown in FIG. 6C, when the subject is in a “slow running” state, the cycle of the left and right sensors is determined by the stride to run, and the cycle is substantially constant. In this case, the amplitude of the left and right sensors is slightly larger than the “walking” state. Further, as shown in FIG. 6D, when the subject is in a “running” state, the cycle of the left and right sensors is determined by the stride to run, and the cycle is substantially constant. In this case, the amplitude of the left and right sensors is considerably larger than in the “walking” state or the “slow walking” state.

  FIG. 7 is a diagram showing how the amplitude of acceleration time change data changes with time for each of the states of “standing quietly”, “walking”, “running slowly”, and “running”. It is. As described above, it is clear from FIG. 7 that a difference occurs in the magnitude of the amplitude for each state. FIG. 8 shows a measured value for each state, that is, a period of time change data of acceleration data (hereinafter referred to as “acceleration data period”) and an amplitude of time change data of acceleration data (hereinafter referred to as “acceleration data amplitude”). FIG.

  As shown in FIG. 8, it has been clarified through experiments that a predetermined area is defined depending on the states of “stand quietly”, “walk”, “run slowly”, and “run”. In other words, it is clear that “stand quietly” is in the P region, “walk” is in the Q region, “run slowly” is in the R region, and “run” is in the S region. Therefore, in this embodiment, as shown in FIG. 9, each region of P, Q, R, and S is defined, and if it enters any of these regions, it is determined that the corresponding state is reached. did. The values on the horizontal axis and the vertical axis are relative values and are arbitrarily scaled.

  Here, it supplements further about each said area | region P, Q, R, S of FIG. The region P gathers in a region near the origin. In the region Q, the amplitude of the acceleration data is small, but the acceleration data cycle varies. In the region R, the amplitude of the acceleration data is larger than that of the region Q, but the acceleration data period varies to the same extent as the region Q. In the region S, the amplitude of the acceleration data is the largest, but the acceleration data period varies to the same extent as the region Q.

  Hereafter, with reference to the flowchart of FIG. 10, the operation | movement by the action monitoring system which concerns on one embodiment of this invention is demonstrated in detail.

  When the operation starts, the center device 2 initializes the variable I (I = 0) (step S1), and then performs wireless communication with the sensor unit 1. As a result, the center device 2 stores the acceleration data in the acceleration data storage unit 24a of the sensor data collection processing unit 24. The stored acceleration data A (I) and A (I + 1) are read (step S2). Subsequently, the period / amplitude analysis unit 24b determines whether or not the amplitude of the acceleration data A (I) is maximum or minimum from the acceleration data A (I) and A (I + 1) (step S3).

  If it is determined in step S3 that the amplitude of the acceleration data A (I) is not maximum or minimum, the variable I is incremented (I = I + 1) (step S4), and then the variable I is the number of sampling units N (Step S5), if I = N, the operation is terminated, and if I = N, the process returns to step S2 to repeat the above operation.

  On the other hand, if it is determined in step S3 that the amplitude of the acceleration data A (I) is maximum or minimum, it is subsequently determined whether the amplitude of the acceleration data A (I) is maximum or minimum (step S6). ). Here, when it is determined that the amplitude of the acceleration data A (I) is minimal, the amplitude at the minimum is Pmin (I), and the time is Tmin (I) (step S7). Is determined to be Pmax (I) at the maximum and Tmax (I) as the time (step S8), and if the maximum and minimum data are aligned, or one is updated, either one is updated. (Step S9). If it is determined that the maximum and minimum data are not complete or one of them has not been updated, the variable I is incremented (I = I + 1) (step S10), and then the process proceeds to step S5 and the above processing is performed. Do. On the other hand, if it is determined that the maximum and minimum data have been prepared or one of them has been updated, the period Tmax (I) −Tmin (I) and the amplitude difference Pmax (I) −Pmin ( I) is calculated (step S11).

  Subsequently, the behavior determination unit 24c determines which of the regions P, Q, R, and S in the acceleration data cycle-acceleration data amplitude graph shown in FIG. The behavior state of the subject is determined from the determination result (steps S12 to S19). More specifically, the behavioral state determination unit 24c determines that the converted data is in the “quietly standing” state when the converted data is included in the region P (steps S12 and S13), and is included in the region Q. In this case, it is determined that the vehicle is in a “walking” state (steps S14 and S15), and if it is included in the region R, it is determined that it is in a “run slowly” state (steps S16 and 17). If it is determined that it is in the “running” state (steps S18 and S19), the variable I is incremented (I = I + 1), the process returns to step S5, and the above operation is repeated.

  As described in detail above, according to an embodiment of the present invention, it is not necessary to obtain initial value information that may be used, such as using another means or increasing cumulative error, and directly from the measured value of the acceleration sensor. In addition, the posture of the subject can be detected with high accuracy.

  Of course, the present invention is not limited to the above-described embodiment, and various improvements and modifications can be made without departing from the spirit of the present invention. For example, it is possible to adopt a configuration in which, for example, a two-axis or three-axis acceleration sensor is employed, the output of the two-axis or three-axis acceleration sensor is processed, and behavior monitoring is possible.

It is a block diagram of the action monitoring system which concerns on one embodiment of this invention. 3 is a diagram illustrating a configuration example of a sensor unit 3. FIG. 3 is a diagram illustrating a configuration example of a sensor unit 4. FIG. FIG. 2 is a diagram illustrating a detailed configuration of a sensor drive control unit 12 and a sensor unit 11 that are components of the sensor unit 1. 3 is a diagram illustrating a detailed configuration of a sensing signal transmission unit 13 and a sensor driving signal reception unit 15 that are components of the sensor unit 1. FIG. (A) thru | or (d) is a figure which shows the change of the action of the subject equipped with the sensor unit 1 which the action monitoring system which concerns on this one Embodiment employ | adopts. It is the figure which showed how the amplitude of the time change data of an acceleration changes with time changes about each state of "standing quietly", "walking", "running slowly", and "running". It is a figure which shows the relationship between the acceleration data period in each state, and acceleration data amplitude. It is the figure which defined area | region P, Q, R, and S for determining action. It is a flowchart for demonstrating in detail the operation | movement by the action monitoring system which concerns on one embodiment of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1, 3, 4 ... Sensor unit, 2 ... Center apparatus, 11 ... Sensor, 12 ... Sensor drive control part, 13 ... Sensing signal transmission part, 14 ... Antenna part, 15 ... Sensor drive signal receiving part, 16 ... Battery, 21 ... Antenna part, 22 ... Signal distribution part, 23 ... Reception part, 24 ... Sensor data collection processing part, 25 ... Sensor control part, 26 ... Transmission part.

Claims (3)

A sensor unit mounted on a subject and a center device are configured to be communicable, and are behavior monitoring systems that monitor behavior related to the subject,
A sensor unit having an acceleration sensor and communication means for transmitting acceleration data measured by the acceleration sensor to the center device as a sensing signal;
The period / amplitude analysis unit that receives the sensing signal sent from the communication means in time series and analyzes the period / amplitude of the time-series acceleration data included in the sensing signal, and the acceleration data period obtained by this analysis A center device having a behavior state determination unit for determining a behavior state of the subject based on the acceleration data amplitude;
A behavior monitoring system comprising: A sensor unit mounted on a subject and a center device are configured to be communicable, and are behavior monitoring systems that monitor behavior related to the subject,
A sensor unit having an acceleration sensor and a storage unit for storing acceleration data measured by the acceleration sensor;
Acceleration data is read from the storage unit in time series, the period / amplitude analysis unit for analyzing the period / amplitude of the time series acceleration data, and the acceleration data period and acceleration data amplitude obtained by the analysis are analyzed. A center apparatus having an action state determination unit for determining an action state of the specimen;
A behavior monitoring system comprising:   The behavior state determination unit further refers to a table that defines a predetermined region, and determines a behavior state based on a region to which the converted data belongs. The behavior monitoring system described in 1.

Images