JP2019146965A - Biological information measuring device, biological information measuring method, and program - Google Patents

Abstract

To provide a biological information measuring device, a biological information measuring method and a program which can contribute to establishment of an early detection technique of a respiratory disease.SOLUTION: A sound wave sensor 10 detects sound waves propagating inside the living body of a pig P. On the basis of a sound signal detected by the sound wave sensor 10, an information detection unit 3 detects information on the breath sound of the pig P. On the basis of the sound signal detected by the sound wave sensor 10, the information detection unit 3 detects information on the heartbeat of the pig P. The information detection unit 3 generates a power signal obtained by squaring the sound signal detected by the sound wave sensor 10, detects the information on the heartbeat of the pig P on the basis of the peak of the power signal, and detects the information on the breath sound of the pig P on the basis of an envelope of the peak of the power signal. The number of zero crossings, detection of mel frequency cepstrum coefficient, and wavelet analysis may be used in some cases.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a biological information measuring device, a biological information measuring method, and a program.

  Although livestock breeding is progressing on a large scale, it reduces production costs by preventing wear and reduces the use of antibacterial agents and other chemicals to produce healthy livestock. It is pointed out that it is necessary to take measures against diseases such as cattle pneumonia that inhibit the productivity of livestock (see Non-Patent Document 1, for example). In group feeding, if one animal suffers from infectious respiratory disease, the disease spreads in groups, leading to significant wear. For this reason, early detection and early treatment of disease signs are required, and development of a technology that can detect signs of respiratory disease from biological signals of livestock is expected. In response, diagnosis of respiratory disease has been attempted from coughing of pigs through sound monitoring using a microphone installed in a breeding house (see, for example, Non-Patent Document 2).

Recent situation on livestock hygiene (February 2018), Ministry of Agriculture, Forestry and Fisheries http://www.maff.go.jp/j/syouan/douei/katiku_yobo/attach/pdf/index-114.pdf, 2018 See February 22 C. Yongwha, et al., "Automatic Detection and Recognition of Pig Wasting Diseases Using Sound Data in Audio Surveillance Systems", Sensors 2013, 13 (10), 12929-12942.

  In pig farming, etc., large-scale management and multi-headed breeding have been promoted, and the importance of hygiene management has increased. In particular, technology for early detection of respiratory diseases caused by mixed infections that have a large impact and greatly affect livestock management Establishment of is desired.

  The present invention has been made in view of the above circumstances, and an object thereof is to provide a biological information measuring device, a biological information measuring method, and a program that can contribute to the establishment of a technology for early detection of respiratory diseases.

The biological information measuring apparatus according to the first aspect of the present invention provides:
A sound wave sensor for detecting a sound wave propagating in the living body of the subject;
An information detection unit that detects information related to the breathing sound or heartbeat of the subject based on a sound signal detected by the acoustic wave sensor;
Is provided.

The information detection unit
Generating a power signal obtained by squaring the sound signal detected by the acoustic wave sensor;
Detecting information related to the respiratory sound of the subject based on an envelope of a plurality of peaks appearing in the power signal;
It is good as well.

In addition, the information detection unit
Interpolating a plurality of peaks appearing in the power signal and connecting them with a line to generate the envelope;
It is good as well.

The information detection unit
Generating a power signal obtained by squaring the sound signal detected by the acoustic wave sensor;
Detecting information about the heartbeat of the subject based on the peak of the power signal;
It is good as well.

The information detection unit
Detecting the number of zero crossings, which is the number at which the waveform of the sound signal detected by the sound wave sensor intersects a zero level or a constant section near the zero level, as information related to the respiratory sound of the subject
It is good as well.

The information detection unit
Detecting a mel frequency cepstrum coefficient of the sound signal as information on a breathing sound of the subject;
It is good as well.

The information detection unit
Detecting information related to the health condition of the subject based on a change in the mel frequency cepstrum coefficient from the first to the sixth in order of decreasing order;
It is good as well.

The information detection unit
Wavelet transform is performed on the sound signal detected by the acoustic wave sensor to detect information related to the respiratory sound or heartbeat of the subject.
It is good as well.

The information detection unit
Extract a part of the waveform of the sound signal detected by the acoustic wave sensor,
Using the extracted waveform as a mother wavelet, performing wavelet transformation to detect information on the respiratory sound or heartbeat of the subject,
It is good as well.

The subject is livestock,
The acoustic wave sensor is attached to a surface in contact with the ear in the ear tag.
It is good as well.

The sensor output of the acoustic wave sensor is transmitted to the information detection unit via wireless communication.
It is good as well.

The acoustic wave sensor is attached to a plurality of subjects,
The information detection unit
Collecting biological information obtained based on sound signals detected by the sound wave sensors attached to the plurality of subjects, respectively, and managing each of the subjects;
It is good as well.

The acoustic wave sensor is a piezo microphone.
It is good as well.

The biological information measuring method according to the second aspect of the present invention includes:
A detection step in which a sound wave sensor detects a sound wave propagating inside the living body of the subject;
An information detecting step in which a computer detects information related to a breathing sound or heartbeat of the subject based on a sound signal detected by the sound wave sensor;
including.

The program according to the third aspect of the present invention is:
Computer
A heart rate information detector that detects information related to the heart rate of the subject based on a peak of a power signal obtained by squaring a sound signal propagating through the body of the subject detected by the acoustic wave sensor;
A respiration information detection unit for detecting information related to the respiration sound of the subject based on the peak envelope of the power signal;
To function as.

  According to the present invention, information on respiratory sounds and heartbeats is acquired based on sound waves propagating through the body of a subject. Information regarding respiratory sounds and heartbeats is information that contributes to the establishment of early detection technology for respiratory diseases. That is, according to the present invention, information that contributes to establishment of an early detection technique for respiratory diseases can be detected by a simple method of measuring sound waves that propagate in the body of a subject.

It is a block diagram which shows the structure of the biometric information measuring apparatus which concerns on Embodiment 1 of this invention. It is a graph which shows an example of the sound signal detected with the sound wave sensor. It is a graph which shows an example of the power signal of a sound signal. It is a graph which shows an example of the envelope obtained by interpolating the peak of a power signal. It is a block diagram which shows the hardware constitutions of the information detection part of FIG. It is a flowchart which shows the flow of a process of the information detection part of FIG. 1 is a diagram showing a system configuration for managing a plurality of subjects. FIG. It is a block diagram which shows the structure of the biometric information measuring apparatus which concerns on Embodiment 2 of this invention. It is a figure which shows the number of zero crossings. It is a figure which shows the change of the zero crossing number of the sound signal detected with the sound wave sensor before and behind virus inoculation. It is a figure which shows the change of MFCC (1) of the sound signal detected with the sound wave sensor before and behind virus inoculation. It is a figure which shows the change of MFCC (2) of the sound signal detected with the sound wave sensor before and behind virus inoculation. It is a figure which shows the change of MFCC (3) of the sound signal detected with the sound wave sensor before and behind virus inoculation. It is a figure which shows the p value of the test result implemented with respect to each elapsed days before and after virus inoculation. It is a block diagram which shows the structure of the biometric information measuring apparatus which concerns on Embodiment 3 of this invention. (A) is a figure which shows the raw waveform of the sound signal extracted from the sound wave sensor 10. FIG. (B) And (C) is a figure which shows a waveform when wavelet transformation is performed with respect to the waveform of (A). (A) is a figure which shows a heart sound waveform. (B) is a figure which shows the waveform which (A) wavelet-transformed. (C) is a figure which shows the envelope waveform of (B). It is a flowchart which shows operation | movement of the biometric information measuring apparatus of FIG. (A) is a figure which shows a heart sound space | interval when a Morlet wavelet is used as a mother wavelet. (B) is a diagram showing a heart sound interval when a part of a sound signal is used as a mother wavelet.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In all drawings, the same or corresponding components are denoted by the same reference numerals.

Embodiment 1 FIG.
First, the first embodiment of the present invention will be described. As shown in FIG. 1, the biological information measuring device 1 is used to measure biological information of a pig P as a subject. The biological information measuring device 1 includes a sensor unit 2 and an information detection unit 3.

  The pig P is a domestic animal, and an ear tag S on which an identification number is displayed is attached to its ear. The sensor unit 2 is attached to the ear tag S. The information detection unit 3 can wirelessly communicate with the sensor unit 2, receives a signal transmitted from the sensor unit 2, and performs signal processing on the signal.

  The sensor unit 2 includes a sound wave sensor 10, an amplifier unit 11, and a transmission device 12. The sound wave sensor 10, the amplifier unit 11, and the transmission device 12 are incorporated in the ear tag S.

  The acoustic wave sensor 10 is in contact with the surface of the ear of the pig P and detects a sound wave signal (sound signal) propagating through the living body of the pig P as the subject. As the acoustic wave sensor 10, for example, a piezo microphone is used. The piezo microphone is composed of a piezoelectric element. The piezo microphone vibrates according to the vibration of the living body surface that vibrates with the sound wave propagating inside the living body of the pig P, and outputs an electric signal corresponding to the sound signal.

  The amplifier unit 11 is an amplifier circuit that amplifies and outputs the electrical signal output from the acoustic wave sensor 10.

  The transmission device 12 transmits the sound signal detected by the sound wave sensor 10 to the information detection unit 3 by wireless communication. In the present embodiment, communication using FM (Frequency Modulation) waves is adopted as wireless communication. Specifically, the sound signal detected by the sound wave sensor 10 is modulated into an FM wave and output from the antenna.

  The information detection unit 3 detects information related to the breathing sound of the pig P based on the sound signal detected by the sound wave sensor 10. Furthermore, the information detection unit 3 detects information related to the heartbeat of the pig P based on the sound signal detected by the sensor unit 2.

  More specifically, the information detection unit 3 is a computer (information processing apparatus). The information detection unit 3 includes a receiving device 13, a heartbeat information detection unit 14, a respiration information detection unit 15, an output unit 16, and a storage unit 17.

  The receiving device 13 is an FM wave receiving device that receives a sound signal transmitted from the transmitting device 12 by wireless communication. Specifically, the receiving device 13 demodulates and outputs a sound signal from the received FM wave signal. FIG. 2 shows an example of the sound signal demodulated and output in this way.

  The heart rate information detection unit 14 detects information related to the heart rate of the pig P based on the sound signal received by the receiving device 13. Specifically, the heart rate information detection unit 14 squares the sound signal shown in FIG. 2, for example, and generates a power signal thereof. FIG. 3 shows this power signal. In this power signal, a peak having a level equal to or higher than a threshold value is generated. The period in which the peak of the power signal occurs matches the heartbeat period of the pig P. That is, the generation cycle of the peak of the power signal corresponds to information related to the heartbeat.

  The respiratory information detection unit 15 detects information related to the respiratory sound of the pig P based on the received sound signal. Specifically, the respiratory information detection unit 15 generates, for example, a peak envelope of the power signal of the sound signal illustrated in FIG. FIG. 4 shows the peak envelope of this power signal.

  The output unit 16 outputs information on the detected heartbeat or breathing sound of the pig P to the outside. Specifically, the output unit 16 outputs the heart rate information detected by the heart rate information detection unit 14 and the respiration information detected by the respiration information detection unit 15.

  The memory | storage part 17 memorize | stores the information regarding the received sound signal, the detected heartbeat, or the breathing sound. Specifically, the storage unit 17 stores various signals and information generated by the receiving device 13, the heart rate information detection unit 14, and the respiration information detection unit 15.

  As shown in FIG. 5, the information detection unit 3 includes a control unit 31, a main storage unit 32, an external storage unit 33, an operation unit 34, a display unit 35, and a wireless communication circuit 36 as hardware configurations. The main storage unit 32, the external storage unit 33, the operation unit 34, the display unit 35, and the wireless communication circuit 36 are all connected to the control unit 31 via the internal bus 30.

  The control unit 31 includes a CPU (Central Processing Unit) and the like. The CPU executes various arithmetic processes such as signal squaring and linear interpolation according to a program 39 stored in the external storage unit 33, whereby each of the information detection units 3 of the biological information measuring apparatus 1 shown in FIG. The component is realized.

  The main storage unit 32 is composed of a RAM (Random-Access Memory) or the like. The main storage unit 32 is loaded with a program 39 stored in the external storage unit 33. In addition, the main storage unit 32 is used as a work area (temporary data storage area) of the control unit 31.

  The external storage unit 33 includes a nonvolatile memory such as a flash memory, a hard disk, a DVD-RAM (Digital Versatile Disc Random-Access Memory), and a DVD-RW (Digital Versatile Disc ReWritable). In the external storage unit 33, a program 39 to be executed by the control unit 31 is stored in advance. Further, the external storage unit 33 supplies data used when executing the program 39 to the control unit 31 in accordance with an instruction from the control unit 31, and stores the data supplied from the control unit 31.

  The heart rate information detection unit 14 and the respiratory information detection unit 15 of the information detection unit 3 described above correspond to the control unit 31.

  The operation unit 34 includes a pointing device such as a keyboard and a mouse, and an interface device that connects the keyboard and the pointing device to the internal bus 30. Information regarding the content operated by the operator is input to the control unit 31 via the operation unit 34.

  The display unit 35 is composed of a CRT (Cathode Ray Tube), an LCD (Liquid Crystal Display), or the like. When the operator inputs operation information, an operation screen is displayed. The display unit 35 displays, for example, heart rate information and respiration information. The display unit 35 corresponds to the output unit 16.

  The wireless communication circuit 36 is a communication circuit that receives an FM wave radio signal transmitted from the transmission device 12 of the sensor unit 2. Audio data is received via the wireless communication circuit 36.

  Next, the operation of the biological information measuring apparatus 1 will be described. The sound wave sensor 10 in the sensor unit 2 detects the sound wave in the living body of the pig P constantly or intermittently, amplifies the detected sound signal by the amplifier unit 11, and outputs it to the transmission device 12. The transmission device 12 modulates the sound signal into an FM wave and transmits the FM signal to the reception device 13 of the information detection unit 3 by wireless communication.

  As shown in FIG. 6, in the information detection unit 3, the reception device 13 receives the sound signal transmitted from the transmission device 12 (step S1). FIG. 2 shows an example of the received sound signal. This sound signal is stored in the storage unit 17.

  Subsequently, the heart rate information detection unit 14 squares the received sound signal and generates a power signal (step S2; heart rate information detection step). FIG. 3 shows an example of this power signal. A peak in this power signal indicates a heartbeat sound. The heartbeat information detected by the heartbeat information detector 14 is the time when this peak occurs and the interval (cycle) at that time. This heartbeat information is stored in the storage unit 17.

  Subsequently, the respiration information detection unit 15 performs interpolation of a plurality of peaks generated in the power signal (step S3; respiration information detection step). Specifically, the respiratory information detection unit 15 generates an envelope by connecting a plurality of peaks generated in the power signal by linear interpolation. This envelope is respiration information. FIG. 4 shows this envelope. The envelope detected by the respiration information detection unit 15, that is, respiration information is stored in the storage unit 17.

  Subsequently, the output unit 16 externally outputs the heart rate information detected by the heart rate information detection unit 14 and the respiration information detected by the respiration information detection unit 15 (step S4; output step). Here, for example, these pieces of information are displayed and output on the display unit 35. The heartbeat information and the respiratory information output to the outside are highly likely to be important information for evaluating the health condition of the respiratory system of the pig P (health condition leading to a respiratory disease). Note that steps S3 and S4 correspond to an information detection step.

  Actually, as shown in FIG. 7, the number of pigs P, which are livestock, is managed, and the information detection unit 3 receives sound waves from the plurality of sensor units 2 attached to each pig P. Receive information. In the information detection unit 3, the recognition number of each pig P and data such as sound signals are stored in the storage unit 17 in association with each other, and the health state of each pig P is managed. In this case, there are various methods for associating the recognition number with data such as a sound signal. For example, the channel of the radio signal to be received may be changed for each pig P, and the signal sent as the header of the sound signal may be a signal indicating the identification number. Further, the reception timing may be assigned to each pig P.

  As described above in detail, according to the present embodiment, information on respiratory sounds and heartbeats is acquired based on sound waves propagating through the body of pig P. Information regarding respiratory sounds and heartbeats is information that contributes to the establishment of early detection technology for respiratory diseases. That is, according to the present embodiment, information that contributes to establishment of an early detection technique for respiratory diseases can be detected by a simple method of measuring sound waves that propagate in the body of the pig P.

  In addition, the applicant generates a power signal obtained by squaring the sound signal detected by the sound wave sensor 10, and detects information related to the respiratory sound of the pig P based on the envelope of the peak of the power signal. Successful. It is a new finding that the peak envelope that appears in the power signal of the sound signal in the living body corresponds to the breathing sound of the living body. In the present embodiment, based on this knowledge, information on the respiratory sound of the pig P can be easily measured by signal processing the sound wave propagating through the body of the pig P.

  According to the present embodiment, the envelope of the power signal propagating through the living body is linearly interpolated to generate the envelope. If it does in this way, the information regarding a breathing sound can be easily obtained by signal processing. However, the present invention is not limited to this. Curve interpolation such as spline curve interpolation may be employed to obtain the envelope.

  In addition, the inventors have found as a new finding that the peak of the power signal obtained by squaring the sound signal corresponds to the heartbeat of the living body. In the present embodiment, based on this knowledge, information on the heartbeat of the pig P can be easily measured by signal processing the sound wave propagating through the body of the pig P.

  Further, according to the present embodiment, the subject is a pig P, and the sound wave sensor 10 is attached to the surface of the ear tag S that contacts the ear. If it does in this way, the sound wave which propagates the inside of pig P can be detected, without providing a new wearing tool. The inventors observed sound signals at various positions (for example, near the nose tip, back, and cervical vertebrae) of the living body, and detected information on respiratory sounds and heartbeats from the sound signals. In this case, for the pig P, when the sensor unit 2 is attached to the ear tag S, the information about the heartbeat and the breathing sound can be detected.

  Moreover, according to this Embodiment, the sensor output of the sensor part 2 is transmitted to the information detection part 3 by radio | wireless communication. In this way, the sensor unit 2 and the information detection unit 3 can be physically separated. In the present embodiment, the wireless communication is FM wave communication, but the present invention is not limited to this. The frequency band of the radio signal may be another frequency band, and other communication methods such as short-range communication incorporated in the mobile terminal may be adopted.

  The information detection unit 3 collects sensor outputs from the plurality of sensor units 2 and measures biological information of a large number of pigs P. If it does in this way, the health state of many pigs P can be managed collectively.

Embodiment 2. FIG.
Next, a second embodiment of the present invention will be described. In the present embodiment, the number of zero crossings and Mel frequency cepstrum analysis (for example, cepstrum analysis or LPC (linear Prediction Coding) mel cepstrum calculation) is performed to detect biological information of the pig P as the subject. As shown in FIG. 8, in the present embodiment, the configuration of the information detection unit 3 is different from that of the first embodiment.

  Specifically, in the present embodiment, the information detection unit 3 includes a zero-crossing number detection unit 20 and a mel frequency cepstrum detection unit 21 instead of the heartbeat information detection unit 14 and the respiration information detection unit 15.

  The zero-crossing number detection unit 20 detects the number of zero-crossings of the waveform of the sound signal detected by the sound wave sensor 10 as information on the respiratory sound of the pig P using the zero-cross method. More specifically, the zero-crossing number detection unit 20 extracts sound data of a section to be determined from sound signals detected by the sound wave sensor 10. Here, first, audio data for a certain period (one frame) is extracted. The zero-crossing number detection unit 20 detects a zero-crossing point (see FIG. 9) where the waveform of the sound data crosses the zero level, and detects the number as the number of zero-crossings.

  Thus, the number of zero crossings is a number at which the signal level crosses a zero level or a constant section near the zero level. If the number of zero crossings of the sound in the body of the pig P increases, it is suspected that the pig P is suffering from respiratory illness and the health condition has deteriorated. Therefore, the zero crossing number detection unit 20 detects the number of zero crossings in the waveform of the sound signal detected by the sound wave sensor 10.

  The mel frequency cepstrum detection unit 21 detects the mel frequency cepstrum coefficient of the sound signal detected by the sound wave sensor 10 as information on the respiratory sound of the pig P.

(Mel frequency cepstrum analysis)
Details of the mel frequency cepstrum analysis will be described. In the present embodiment, the mel frequency cepstrum coefficient of the extracted audio data for a certain period is detected. The mel frequency cepstrum coefficient is generally used as an acoustic feature quantity. Here, the cepstrum is the result of frequency conversion (for example, Fourier transform) by regarding the sound spectrum as a signal. If the cepstrum is used, the sound spectrum can be expressed with a small number of parameters, and the fine structure of the spectrum and the spectrum envelope can be easily separated. Mel indicates that the coefficient is calculated in consideration of the characteristics of human speech perception. If the mel cepstrum is used, the low frequency region can be finely sampled according to the human auditory characteristics.

First, the mel frequency cepstrum detection unit 21 emphasizes the high frequency component of the waveform of the audio data with a pre-emphasis filter. The pre-emphasis filter is used to clearly show vocal tract characteristics by enhancing high frequency components. For example, the following formula can be adopted as the filter calculation formula.
y (n) = x (n) -px (n-1)
Here, n is a natural number and a sampling number. Further, x (n) is the sound waveform data for determination, and x (n−1) is the value of the previous sound data. p is a pre-emphasis coefficient, and 0.97 is often used, but the value to be set is arbitrary. Y (n) is the output of the filter.

  Further, the mel frequency cepstrum detection unit 21 performs fast Fourier transform (FFT) on the audio data in which the high frequency component is emphasized after applying a window function (such as a Hamming window) to obtain an amplitude spectrum of the audio data.

  Subsequently, the mel frequency cepstrum detector 21 compresses the amplitude spectrum by applying a mel filter bank. A mel filter bank is, for example, a plurality of triangular bandpass filters arranged side by side, and is a filter bank that is equally spaced on the mel scale. The mel scale is a frequency axis reflecting human speech perception, and its unit is mel. In other words, the band-pass filters of the mel filter bank are narrow in the low frequency range and wide in the high frequency range. The number of bandpass filters is called the number of channels.

  Further, the mel frequency cepstrum detection unit 21 regards the compressed numerical sequence as a signal and performs a discrete cosine transform to obtain a cepstrum. The low-order component of the obtained cepstrum is a mel frequency cepstrum coefficient (MFCC), and the mel frequency cepstrum detection unit 21 extracts the MFCC. The MFCC is expressed as MFCC (1) to MFCC (20) in order from the lowest order.

  If the Mel frequency cepstrum coefficient (MFCC) of the sound in the body of the pig P changes, it is suspected that the pig P is suffering from respiratory illness and the health condition has deteriorated. Therefore, the mel frequency cepstrum detection unit 21 detects the mel frequency cepstrum coefficient (MFCC) of the waveform of the sound signal detected by the sound wave sensor 10 as information related to the respiratory sound of the pig P.

  For example, porcine reproductive and respiratory syndrome (PRRS) virus was administered to pigs, and analysis using the zero-cross method was performed on body conduction sounds collected from the ears of infected individuals. Signal collection was performed before virus inoculation, 3 days, 5 days, 7 days, and 10 days after inoculation. As shown in FIG. 10, FIG. 11, FIG. 12 and FIG. 13, when the number of zero crossings before virus inoculation, the second quartile (median value) of MFCC (1) to MFCC (3), The third quartile changes greatly after 3 days, 5 days, 7 days, and 10 days after inoculation. The zero-crossing number detection unit 20 and the mel frequency cepstrum detection unit 21 detect such a change as a change in the respiratory sound of the pig P, that is, a change in the health state.

  In addition, as shown in FIGS. 10, 11, 12, and 13, before the virus inoculation, the number of zero crossings indicated in the quartile range, MFCC (1) to MFCC (3) variation, that is, the quadrant Although the rank range was large, after the third day of inoculation, the variation in the number of zero crossings and MFCC (1) to MFCC (3) (quartile range) is small. The zero-crossing number detection unit 20 may detect such a variation in the variation in the number of zero-crossings, MFCC (1) to MFCC (3), as a change in the health state of the pig P.

  As can be seen by comparing the p-values of the test results carried out for each elapsed day before and after virus inoculation in FIG. 14, the number of zero crossings, MFCC (1) before and after the virus inoculation. , MFCC (2), MFCC (3), MFCC (4), MFCC (5) and MFCC (6), significant differences were confirmed. Here, FIG. 14 is a result of multiple comparison of analysis results by Tukey-Kramer HSD test. * Indicates a significant difference at the 5% level, and ** indicates a significant difference at the 1% level. Therefore, if the information detection part 3 detects the information regarding the health condition of the pig P based on the change of the mel frequency cepstrum coefficients MFCC (1) to MFCC (6) from the first to the sixth in order from the lowest order. Good.

Embodiment 3 FIG.
Next, a third embodiment of the present invention will be described. In this embodiment, wavelet transformation is performed. As shown in FIG. 15, in the present embodiment, the configuration of the information detection unit 3 is different from that of the first embodiment.

  The information detection unit 3 includes a wavelet analysis unit 25 instead of the heartbeat information detection unit 14 and the respiratory information detection unit 15. The wavelet analysis unit 25 performs wavelet transform on the sound signal detected by the sound wave sensor 10 to detect information related to the respiratory sound or heartbeat of the pig P.

  For the wavelet transform, an analyzing wavelet (mother wavelet) that performs a correlation operation with a sound signal is used. Although any mother wavelet can be used, in this embodiment, a general Morlet wavelet is used.

  When a sound signal as shown in FIG. 16A (a raw waveform of a body conduction sound collected from the ear of pig P) is acquired, the wavelet analysis unit 25 changes the scale of the Morlet wavelet, Correlation with the Morlet wavelet, that is, wavelet transform is performed on the waveform. Then, a respiratory sound waveform (scale 440) as shown in FIG. 16B and a heart sound waveform (scale 10) as shown in FIG. 16C are extracted. Circles in the figure indicate extracted respiratory sounds and heartbeat peaks.

  Since the low frequency of the data transferred by FM communication is attenuated, the low frequency power such as breathing sound and heartbeat is attenuated. However, in recent years, the low frequency characteristics have been improved by improving the system. For this reason, it has become possible to extract respiratory sounds appearing at low frequencies and vibrations of the heartbeat itself by wavelet analysis. Since the wavelet analysis can extract a minute time variation of the signal, the respiratory rate and the heart rate can be measured more accurately.

  As the sound signal, a heart sound waveform (FIG. 17A) measured with a stethoscope or the like may be used. In this case, as shown in FIG. 18, the biological information measuring apparatus 1 measures the heart waveform of the sound wave sensor 10 (step S11). Subsequently, the biological information measuring apparatus 1 (wavelet transform unit 25) performs real signal wavelet transform (step S12). Furthermore, the biological information measuring device 1 (wavelet conversion unit 25) squares the converted waveform and converts it into a power signal (FIG. 17B) (step S13). Furthermore, the biological information measuring device 1 (wavelet transform unit 25) creates an envelope (FIG. 17C) of the power signal (step S14). Furthermore, the biological information measuring apparatus 1 (wavelet transform unit 25) extracts one and two heart sounds (step S15), and calculates a heart sound interval with the odd number as one sound (step S16). Then, the biological information measuring apparatus 1 (wavelet transform unit 25) creates a trendgram as shown in FIGS. 19A and 19B (step S17).

  In the present embodiment, the Morlet wavelet is used as the mother wavelet, but the present invention is not limited to this. An arbitrary waveform can be used as the mother wavelet. For example, a waveform (instantaneous correlation function) of a certain time extracted from the sound signal of the sound wave sensor 10 can be used as the mother wavelet. In this case, the waveform of one heart sound waveform can be used as an instantaneous correlation function. FIG. 19A shows variations in heart sound intervals when no wavelet is used, and FIG. 19B shows variations in heart sound intervals when a part of a sound waveform is used as a mother wavelet. It is shown. As can be seen from comparison of these waveforms, if a part of the heart sound waveform is used as the mother wavelet, more accurate wavelet analysis can be performed.

  As described above, if the wavelet analysis is used, it is possible to extract a minute time fluctuation of a signal, and thus it is possible to detect a respiratory sound and a heartbeat with a high S / N ratio.

  As described above, according to each of the above-described embodiments, a biological signal of a domestic animal can be extracted without being affected by external noise or sound generated by other domestic animals by using the body conduction sound.

  In addition, according to each of the above embodiments, since the heart sound can be extracted by internal conduction, the state of the livestock is determined by determining the state of the autonomic nerve by performing signal processing on the extracted heart sound waveform. can do.

  Moreover, according to each said embodiment, since a respiratory sound can be extracted by internal conduction, the diseased state of livestock can be judged from the respiratory sound itself in addition to the heart sound. Furthermore, it is possible to construct a centralized management system capable of extracting and accumulating information on heart sounds and breathing sounds with a small terminal installed in the pig P and transmitting it once in a fixed time.

  In each of the above embodiments, only the sensor unit 2 is attached to the subject, but the present invention is not limited to this. The sensor unit 2 and the information detection unit 3 may be attached to the subject. Even in this case, the information detected by the information detection unit 3 can be sent to the central management computer and managed collectively by the management computer.

  In each of the above embodiments, the subject is a pig P. However, the present invention is not limited to this. The subject may be a cow or other livestock. In addition, the biological information measuring apparatus 1 according to the present embodiment can be applied to any subject that can be transmitted in vivo and can observe sound waves related to heartbeat and respiration.

  In addition to breathing sounds and heartbeat sounds, sound waves propagating in the living body include coughing, sneezing, chewing sounds when eating food, drinking sounds, exercise and peristaltic sounds of the intestinal tract. Therefore, the biological information measuring apparatus 1 may capture those sound signals and extract information such as cough from the sound signals.

  Further, in each of the above embodiments, the information detection unit 3 of the biological information measuring device 1 may be realized using a general computer such as a portable terminal or a personal computer, or may be realized as a dedicated device. Good.

  In addition, the hardware configuration and software configuration of the information detection unit 3 are merely examples, and can be arbitrarily changed and modified.

  The central part that performs processing of the information detection unit 3 including the control unit 31, the main storage unit 32, the external storage unit 33, the operation unit 34, the display unit 35, the wireless communication circuit 36, the internal bus 30, and the like is described above. As described above, it can be realized by using a normal computer system regardless of a dedicated system. For example, a computer program for executing the above operation is stored in a computer-readable recording medium (flexible disk, CD-ROM, DVD-ROM, etc.) and distributed, and the computer program is installed in the computer. Thus, the information detection unit 3 that executes the above-described processing may be configured. Alternatively, the biological information measuring device 1 may be configured by storing the computer program in a storage device included in a server device on a communication network such as the Internet, and downloading it by a normal computer system.

  When realizing the function of a computer by sharing an OS (operating system) and an application program, or by cooperation between the OS and an application program, only the application program portion may be stored in a recording medium or a storage device.

  It is also possible to superimpose a computer program on a carrier wave and distribute it via a communication network. For example, a computer program may be posted on a bulletin board (BBS, Bulletin Board System) on a communication network, and the computer program distributed via the network. The computer program may be started and executed in the same manner as other application programs under the control of the OS, so that the above-described processing may be executed.

  Various embodiments and modifications can be made to the present invention without departing from the broad spirit and scope of the present invention. The above-described embodiments are for explaining the present invention and do not limit the scope of the present invention. In other words, the scope of the present invention is shown not by the embodiments but by the claims. Various modifications within the scope of the claims and within the scope of the equivalent invention are considered to be within the scope of the present invention.

  The present invention can be applied to detecting information related to the breathing sound and heartbeat of a subject.

  DESCRIPTION OF SYMBOLS 1 Biological information measuring device, 2 Sensor part, 3 Information detection part, 10 Sound wave sensor (piezo microphone), 11 Amplifier part, 12 Transmission apparatus, 13 Reception apparatus, 14 Heart rate information detection part, 15 Respiration information detection part, 16 Output part , 17 storage unit, 20 zero crossing number detection unit, 21 mel frequency cepstrum detection unit, 25 wavelet analysis unit, 30 internal bus, 31 control unit, 32 main storage unit, 33 external storage unit, 34 operation unit, 35 display unit, 36 wireless communication circuit, 39 program, P pig (subject), S ear tag

Claims (15)

A sound wave sensor for detecting a sound wave propagating in the living body of the subject;
An information detection unit that detects information related to the breathing sound or heartbeat of the subject based on a sound signal detected by the acoustic wave sensor;
A biological information measuring device comprising: The information detection unit
Generating a power signal obtained by squaring the sound signal detected by the acoustic wave sensor;
Detecting information related to the respiratory sound of the subject based on an envelope of a plurality of peaks appearing in the power signal;
The biological information measuring device according to claim 1. The information detection unit
Interpolating a plurality of peaks appearing in the power signal and connecting them with a line to generate the envelope;
The biological information measuring device according to claim 2. The information detection unit
Generating a power signal obtained by squaring the sound signal detected by the acoustic wave sensor;
Detecting information about the heartbeat of the subject based on the peak of the power signal;
The biological information measuring device according to claim 1. The information detection unit
Detecting the number of zero crossings, which is the number at which the waveform of the sound signal detected by the sound wave sensor intersects a zero level or a constant section near the zero level, as information related to the respiratory sound of the subject
The biological information measuring device according to claim 1. The information detection unit
Detecting a mel frequency cepstrum coefficient of the sound signal as information on a breathing sound of the subject;
The biological information measuring device according to claim 1. The information detection unit
Detecting information related to the health condition of the subject based on a change in the mel frequency cepstrum coefficient from the first to the sixth in order of decreasing order;
The biological information measuring device according to claim 6. The information detection unit
Wavelet transform is performed on the sound signal detected by the acoustic wave sensor to detect information related to the respiratory sound or heartbeat of the subject.
The biological information measuring device according to claim 1. The information detection unit
Extract a part of the waveform of the sound signal detected by the acoustic wave sensor,
Using the extracted waveform as a mother wavelet, performing wavelet transformation to detect information on the respiratory sound or heartbeat of the subject,
The biological information measuring device according to claim 8. The subject is livestock,
The acoustic wave sensor is attached to a surface in contact with the ear in the ear tag.
The biological information measuring device according to any one of claims 1 to 9. The sensor output of the acoustic wave sensor is transmitted to the information detection unit via wireless communication.
The biological information measuring device according to any one of claims 1 to 10. The acoustic wave sensor is attached to a plurality of subjects,
The information detection unit
Collecting biological information obtained based on sound signals detected by the sound wave sensors attached to the plurality of subjects, respectively, and managing each of the subjects;
The biological information measuring device according to any one of claims 1 to 11. The acoustic wave sensor is a piezo microphone.
The biological information measuring device according to any one of claims 1 to 12. A detection step in which a sound wave sensor detects a sound wave propagating inside the living body of the subject;
An information detecting step in which a computer detects information related to a breathing sound or heartbeat of the subject based on a sound signal detected by the sound wave sensor;
A method for measuring biological information. Computer
A heart rate information detector that detects information related to the heart rate of the subject based on a peak of a power signal obtained by squaring a sound signal propagating through the body of the subject detected by the acoustic wave sensor;
A respiration information detection unit for detecting information related to the respiration sound of the subject based on the peak envelope of the power signal;
Program to function as.

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