JP2008220392A - Biological information measuring apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To accurately measure biological information regardless of the body posture of the subject and by giving no uncomfortable feeling or no unpleasant feeling to the subject. <P>SOLUTION: A biological information measuring apparatus 1 measures the biological information of the subject A using a pressure detecting sensor 10 having a metal base plate and a piezoelectric element arranged on the metal base plate to make output voltage change according to pressure applied from outside. The pressure sensor 10 is arranged in a location coming into no contact with the subject A sandwiching a mattress 3 on which the subject A lies and is arranged at a location near the breast portion of the subject A lying on the mattress 3. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a biological information measuring device that measures biological information of a subject.

  Conventionally, a device for measuring biological information such as breathing and heartbeat of a subject using various pressure sensors has been developed (see, for example, Patent Document 1). This Patent Document 1 is provided on a bedding such as a mattress. There is disclosed an in-bed abnormality monitoring device that detects biological information such as breathing and heartbeat of a subject lying on a piezo sheet and monitors the subject's abnormality.

JP 2002-336207 A

  However, the in-bed abnormality monitoring device disclosed in Patent Document 1 has a problem in that the subject must directly contact the piezo sheet, which gives the subject a sense of discomfort and discomfort due to the piezo sheet. In this way, the subject must contact the piezo sheet directly because the sensitivity of the pressure detection sensor provided on the piezo sheet is not sufficient, and biological information cannot be detected accurately unless the piezo sheet is brought into direct contact with the subject. Because. In addition, when the subject sits on the piezo sheet, the diaphragm and heart move away from the pressure detection sensor of the piezo sheet compared to when the subject lies on the piezo sheet. It was difficult to accurately capture the heart rate.

  Therefore, the present invention has been made to solve the above-described problems, and accurately measures biological information regardless of the posture of the subject and without causing the subject to feel uncomfortable or uncomfortable. It is an object of the present invention to provide a biological information measuring device capable of performing the above.

Means for Solving the Problems and Effects of the Invention

  In order to achieve the above object, a biological information measuring apparatus according to the present invention includes a pressure detection sensor including a metal substrate and a piezoelectric element that is provided on the metal substrate and whose output voltage changes according to pressure applied from the outside. Used to measure the biological information of the subject.

  According to the experiments of the present inventor, it has been found that if a pressure detection sensor provided with a piezo element on a metal substrate is used, a change in pressure related to a minute displacement of the subject due to breathing or heartbeat can be accurately captured. . Further, the inventor of the present application can accurately detect the pressure change related to the minute displacement of the subject due to breathing, heartbeat, etc. even when the pressure detection sensor is not directly in contact with the subject and is placed with a mattress lying on the subject. I confirmed that I could catch it. In addition, the inventor of the present application has disclosed that the breathing and the heart due to the movement of the diaphragm regardless of the body position of the subject, even if the pressure detection sensor is not disposed at a position near the chest where the diaphragm and the heart are located, such as when the subject is sitting on a chair. It was confirmed that the pressure change related to the heartbeat due to the pulsation can be accurately captured.

  Therefore, the biological information measuring apparatus of the present invention that measures biological information of a subject using a pressure detection sensor provided with a piezo element on a metal substrate accurately captures biological information such as respiration and heartbeat regardless of the posture of the subject. be able to. Further, when the pressure detection sensor is arranged with a mattress on which the subject lies, the biological information such as breathing and heartbeat can be accurately captured without causing the subject to feel uncomfortable or uncomfortable.

  In the biological information measuring apparatus, preferably, the pressure detection sensor is disposed at a position where it does not come into contact with the subject with a lying member lying on the subject.

  According to the above configuration, the subject's biological information can be accurately captured without causing the subject lying on the recumbent member to feel uncomfortable or uncomfortable with the pressure detection sensor.

  In this case, preferably, the pressure detection sensor is disposed at a position near the chest of the subject lying on the recumbent member.

  According to the said structure, the heartbeat by the respiration by the motion of a diaphragm and the pulsation of a heart can be detected in the position of the vicinity of a diaphragm and a heart. As a result, the subject's biological information can be captured more accurately without causing the subject to feel uncomfortable or uncomfortable with the pressure detection sensor.

  In the biological information measuring device, preferably, the pressure detection sensor is disposed at a position where the pressure detection sensor does not contact the subject with a seating member on which the subject sits.

  According to the above configuration, the subject's biological information can be accurately captured without giving the subject sitting on the seating member a sense of discomfort or discomfort due to the pressure detection sensor.

  Hereinafter, preferred embodiments of the biological information measuring device of the present invention will be described in detail.

(First embodiment)
FIG. 1 is a schematic diagram showing the overall configuration of the biological information measuring apparatus according to the first embodiment of the present invention, and FIG. 2 is a schematic diagram of a pressure detection sensor of the biological information measuring apparatus shown in FIG. . First, with reference to FIG.1 and FIG.2, the structure of the biological information measuring device 1 which concerns on 1st Embodiment is demonstrated in detail.

  The biological information measuring apparatus 1 according to the present embodiment is an apparatus for measuring respiration and heartbeat of an unconstrained subject A lying on a bed and monitoring information related to the respiration and heartbeat. Note that the above-described non-restraint means a state where a restraint member such as a band for directly attaching a sensor for detecting respiration or heartbeat to the subject A is not attached to the subject A. As shown in FIG. 1, the biological information measuring apparatus 1 includes a pressure detection sensor 10 and a computer 20 connected to the pressure detection sensor 10 so as to be communicable with each other by wire or wirelessly.

  The pressure detection sensor 10 has a function of detecting pressure due to respiration (diaphragm movement) and heartbeat (heart beat) of the subject A lying on the mattress 3. The pressure detection sensor 10 is provided between the bed frame 2 and the mattress 3 placed thereon, and is disposed at a position where the subject A does not contact the subject A across the mattress 3 on which the subject A lies. Further, the pressure detection sensor 10 is disposed at a position near the chest of the subject A lying on the mattress 3. As shown in FIG. 2, the pressure detection sensor 10 includes a stainless steel metal substrate 11, a piezoelectric element 12 bonded to the metal substrate 11, and a conductive film 13.

  The stainless steel metal substrate 11 functions as a reinforcing plate for the piezoelectric element 12 described later. The metal substrate 11 is appropriately adjusted to a thickness capable of distorting a pressure receiving diaphragm (not shown) of the piezo element 12 and a thickness capable of reinforcing the piezo element 12.

  The piezo element 12 changes the magnitude of the output voltage according to the pressure applied from the outside. For this reason, the pressure concerning subject A's breathing and heartbeat can be detected as the output voltage. The piezo element 12 includes a pressure receiving diaphragm that is distorted by receiving pressure applied from the outside, and a detection circuit (not shown) including a piezoresistor whose resistance value changes according to the distortion of the pressure receiving diaphragm. Yes. Therefore, the pressure-receiving diaphragm is distorted by the pressure related to the breathing and heartbeat of the subject A lying on the mattress 3, and the resistance value of the piezoresistor changes. Therefore, the magnitude of the output voltage output from the detection circuit including the piezoresistor Changes.

  The conductive film 13 is made of a metal material such as silver or aluminum, and functions as a conduction path for the output voltage of the piezoelectric element 12 described above. The output voltage of the piezo element 12 is output to the control device 21 of the computer 20 via the conductive film 13.

  The computer 20 analyzes the output voltage input from the piezo element 12 through the conductive film 13 and outputs the analysis result. The computer 20 includes a control device 21, a display device 22, and an input device 23.

  The control device 21 includes a ROM, a CPU, a RAM, a hard disk, an input / output interface, an image output interface, and the like, and these are connected by a bus so that data communication is possible. In addition to the operating system, the hard disk of the control device 21 stores various information such as a respiration / heart rate analysis program and data necessary for executing the respiration / heart rate analysis program.

  This respiration / heart rate analysis program is a program for performing spectrum analysis by FFT (Fast Fourier Transform). If the respiration / heart rate analysis program is used, spectrum analysis of the output voltage detected by the pressure detection sensor 10 is performed. Can be done. Specifically, according to the breathing / heart rate analysis program, a spectrum in a band of about 0.25 Hz indicating breathing performed about once every 4.0 seconds in a resting state, and about 50 to about 90 times per minute in a resting state. It is possible to capture a spectrum in a band of about 0.8 Hz to about 1.5 Hz indicating a heartbeat to be performed.

  An input / output interface of the control device 21 is connected to an input device 23 such as a keyboard and a mouse for inputting various information, and a display device 22 is connected to the image output interface. The display device 22 displays a predetermined image in accordance with the video signal output from the image output interface. Specifically, a graph (see FIGS. 3 to 8) related to spectrum analysis by the above-described respiration / heart rate analysis program is displayed on the display device 22.

  In the first embodiment, as described above, by measuring the biological information of the subject lying on the mattress 3 using the pressure detection sensor 10 in which the piezoelectric element 12 is provided on the stainless steel metal substrate 11, the body position of the subject is measured. Regardless of this, and without causing the subject to feel uncomfortable or uncomfortable, it is possible to accurately grasp the pressure change related to the minute displacement of the subject due to breathing, heartbeat, or the like.

  In the first embodiment, the pressure detection sensor 10 is arranged at a position where the pressure detection sensor 10 is not in contact with the subject A across the mattress 3 on which the subject A lies. Biological information such as the breathing and heartbeat of the subject A can be accurately captured without giving a pleasant feeling.

  Further, in the first embodiment, the pressure detection sensor 10 is disposed in the vicinity of the chest of the subject A lying on the mattress 3, so that the respiration due to the movement of the diaphragm and the heartbeat due to the heartbeat are detected in the vicinity of the diaphragm and the heart. It can be detected by position. As a result, the subject's breathing and heartbeat can be captured more accurately.

(Comparative experiment)
Next, a comparative experiment conducted to confirm the effect of the first embodiment will be described. In this comparative experiment, the biological information measuring apparatus according to Example 1 corresponding to the first embodiment in which a pressure detection sensor is arranged under a spring mattress having a thickness of about 18 cm, and a pressure detection sensor different from the pressure detection sensor. The frequency spectra obtained by the biological information measuring apparatus according to Comparative Example 1 and Comparative Example 2 using the above were compared. In addition, the biological information measuring device according to Example 2 corresponding to the first embodiment in which the pressure detection sensor is arranged under the futon mattress having a thickness of about 5 cm, and a pressure detection sensor different from the pressure detection sensor were used. The frequency spectra obtained by the biological information measuring devices according to Comparative Example 3 and Comparative Example 4 were also compared. The subject lies on the mattress in a supine state, and the pressure detection sensors are all disposed near the chest of the subject who lies. In addition, the subject breathes about once every 4.0 seconds in a resting state (heart rate: about 50 times / minute to about 90 times / minute). Details will be described below.

  As the pressure detection sensor, a sensor having a thickness of about 0.13 mm in which a piezo element was attached to a stainless steel metal substrate was used.

  In the biological information measuring apparatus according to Example 1 using the pressure sensor, as shown in FIG. 3A, a protruding spectrum was observed in the band of about 0.25 Hz. As a result, it was found that in Example 1, the respiratory component was accurately captured.

  Further, in the biological information measuring apparatus according to Example 1, as shown in FIG. 3 (b), a spectral protrusion was observed in a band of about 1.2 Hz. As a result, in Example 1, it was found that the heart rate component was accurately captured.

Comparative Example 1

  As the pressure detection sensor, a sensor having a thickness of about 0.5 mm in which a piezo element was attached to a ceramic substrate was used.

  In the biological information measuring apparatus according to Comparative Example 1 using the pressure sensor, as shown in FIG. 4A, a spectral protrusion was observed in a band of about 0.25 Hz. As a result, it was found that in Comparative Example 1, the respiratory component was accurately captured.

  However, in the biological information measuring apparatus according to Comparative Example 1, as shown in FIG. 4B, no spectral protrusion was observed in the band of about 0.8 Hz to about 1.5 Hz. As a result, in Comparative Example 1, the heart rate component could not be captured.

Comparative Example 2

  As the pressure detection sensor, a sensor having a thickness of about 6.0 mm in which 60 pressure-sensitive points (hereinafter referred to as taxels) are arranged in a matrix is used. In each taxel of this sensor, the intensity of the confused light is measured because the scatter radius of the scattered light emitted from the optical fiber changes due to distortion of the sensing material in which the optical fiber is embedded. By doing so, the measurement applied to each taxel can be performed.

  In the biological information measuring apparatus according to Comparative Example 2 using the pressure sensor, as shown in FIG. 5A, a spectral protrusion was observed in a band of about 0.25 Hz. As a result, it was found that in Comparative Example 2, the respiratory component was accurately captured.

  However, in the biological information measuring apparatus according to Comparative Example 2, as shown in FIG. 5B, no spectral protrusion was observed in the band of about 0.8 Hz to about 1.5 Hz. As a result, in Comparative Example 2, the heart rate component could not be captured.

  When the results of Example 1, Comparative Example 1 and Comparative Example 2 are summarized, as shown in Table 1, when the pressure detection sensor is arranged under a spring mattress having a thickness of about 18 cm, the respiratory component and the heart rate component It was only Example 1 that could catch any of these, and in Comparative Example 1 and Comparative Example 2, the heart rate component could not be caught.

  As a pressure detection sensor, a sensor having a thickness of about 0.13 mm in which a piezo element was bonded to a stainless steel metal substrate was used in the same manner as in Example 1.

  In the biological information measuring apparatus according to Example 2 using the pressure sensor, as shown in FIG. 6A, a spectral protrusion was observed in a band of about 0.25 Hz. As a result, in Example 2, it was found that the respiratory component was accurately captured.

  In addition, in the biological information measuring apparatus according to Example 2, as shown in FIG. 6B, a protruding spectrum was observed in the band of about 1.2 Hz. As a result, in Example 2, it was found that the heartbeat component was accurately captured.

Comparative Example 3

  As a pressure detection sensor, as in Comparative Example 1, a sensor having a thickness of about 0.5 mm in which a piezo element was attached to a ceramic substrate was used.

  In the biological information measuring apparatus according to Comparative Example 3 using the pressure sensor, as shown in FIG. 7A, a spectral protrusion was observed in the band of about 0.25 Hz. As a result, it was found that in Comparative Example 3, the respiratory component was accurately captured.

  Further, in the biological information measuring apparatus according to Comparative Example 3, as shown in FIG. 7B, a protruding spectrum was observed in the band of about 1.1 Hz. As a result, it was found that in Comparative Example 3, the heart rate component was accurately captured.

Comparative Example 4

  As a pressure detection sensor, as in Comparative Example 2, a sensor having a thickness of about 6.0 mm in which 60 taxels are arranged in a matrix is used.

  In the biological information measuring apparatus according to Comparative Example 4 using the pressure sensor, as shown in FIG. 8A, a protruding spectrum was observed in a band of about 0.25 Hz. As a result, it was found that in Comparative Example 4, the respiratory component was accurately captured.

  Moreover, in the biological information measuring device according to Comparative Example 4, as shown in FIG. 8B, a protruding spectrum was observed in the band of about 1.0 Hz to about 1.1 Hz. As a result, it was found that in Comparative Example 4, the heart rate component was accurately captured.

  When the results of Example 2, Comparative Example 3 and Comparative Example 4 are summarized, as shown in Table 2, when the pressure detection sensor is arranged under a futon mattress having a thickness of about 5 cm, Example 2, Both Comparative Example 3 and Comparative Example 4 were able to capture respiratory components and heart rate components.

(Second Embodiment)
FIG. 9 is a schematic diagram showing the overall configuration of the biological information measuring apparatus according to the second embodiment of the present invention. Unlike the biological information measuring apparatus 1 according to the first embodiment for measuring the biological information of the subject lying on the bed, in this second embodiment, the respiration and heart rate of the unconstrained subject A sitting on the chair 102 are measured, The biological information measuring apparatus 100 that monitors information related to the respiration and heartbeat will be described in detail. The second embodiment has the same configuration as that of the first embodiment except that the pressure detection sensor 110 is provided under the mattress 103 placed on the seat surface of the chair 102 on which the subject A sits. The same members are denoted by the same reference numerals, and the description thereof is omitted.

  The pressure detection sensor 110 has a function of detecting the breathing (diaphragm movement) and heartbeat (heartbeat) of the subject A sitting on the chair 102. The pressure detection sensor 110 is provided between the chair 102 and the mattress 103 placed on the seating surface of the chair 102, and is disposed at a position that does not contact the subject with the mattress 103 on which the subject A is seated. Yes.

  In the second embodiment, as described above, by measuring the biological information of the subject seated on the chair 102 using the pressure detection sensor 110 in which the piezoelectric element is provided on the stainless steel metal substrate, the body position of the subject is determined. In addition, it is possible to accurately capture the pressure change related to the minute displacement of the subject due to breathing or heartbeat without causing the subject to feel uncomfortable or uncomfortable.

  Further, in the second embodiment, the pressure detection sensor 110 is placed on the subject A sitting on the mattress 103 by placing the pressure detection sensor 110 at a position that does not contact the subject A across the mattress 103 of the chair 102 on which the subject A sits. The biometric information of the subject A can be accurately captured without giving a sense of discomfort or discomfort due to 110.

(Comparative experiment)
Next, a comparative experiment conducted for confirming the effect of the second embodiment will be described. In this comparative experiment, the biological information measuring device according to Example 3 corresponding to the second embodiment in which the pressure detection sensor is arranged under the mattress placed on the seat surface of the chair, and a pressure different from the pressure detection sensor. The frequency spectra obtained by the biological information measuring apparatus according to Comparative Example 5 using the detection sensor were compared. It is assumed that the subject breathes about once every 4.0 seconds in a resting state (heart rate: about 50 times / minute to about 90 times / minute). Details will be described below.

  As a pressure detection sensor, a sensor having a thickness of about 0.13 mm in which a piezo element is attached to a stainless steel metal substrate was used in the same manner as in Example 1 and Example 2.

  In the biological information measuring apparatus according to Example 3 using the pressure sensor, as shown in FIG. 10 (a), a protruding spectrum was observed in a band of about 0.25 Hz. As a result, in Example 3, it was found that the respiratory component was accurately captured.

  Further, in the biological information measuring apparatus according to Example 3, as shown in FIG. 10B, a protruding spectrum was observed in a band of about 1.1 Hz to about 1.2 Hz. As a result, in Example 3, it was found that the heart rate component was accurately captured.

Comparative Example 5

  As a pressure detection sensor, a sensor having a thickness of about 6.0 mm in which 60 taxels are arranged in a matrix as in Comparative Example 2 and Comparative Example 4 was used.

  In the biological information measuring apparatus according to Comparative Example 5 using the pressure sensor, as shown in FIG. 11 (a), a protruding spectrum was observed in a band of about 0.25 Hz. As a result, it was found that in Comparative Example 5, the respiratory component was accurately captured.

  However, in the biological information measuring device according to Comparative Example 5, as shown in FIG. 11B, no spectral protrusion was observed in the band of about 0.8 Hz to about 1.5 Hz. As a result, in Comparative Example 5, the heartbeat component could not be captured.

  When the results of Example 3 and Comparative Example 5 are summarized, as shown in Table 3, when the pressure detection sensor is arranged under the mattress placed on the seat surface of the chair, in Example 3, respiratory components and heart rate While any of the components could be captured, Comparative Example 5 could not capture the heart rate component.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is shown not by the above description of the embodiment but by the scope of claims for patent, and includes all modifications within the meaning and scope equivalent to the scope of claims for patent.

  For example, in the second embodiment, the example in which the pressure detection sensor is disposed under the mattress placed on the seat surface of the chair has been described. However, the present invention is not limited thereto, and the pressure detection sensor is placed. Even when the subject sits directly on the seating surface of the chair, the respiratory component and the heartbeat component can be accurately captured. As a result of this comparative experiment, in the biological information measuring apparatus according to Example 4 in which the subject directly sits on a chair on which a pressure detection sensor having a piezoelectric element attached to a stainless steel metal substrate is placed, FIG. As shown in (b) and (b), a spectral protrusion was observed in the band of about 0.25 Hz, and a spectral protrusion was observed in the band of about 1.0 Hz to about 1.2 Hz. On the other hand, in the biological information measuring device according to Comparative Example 6 in which the subject is directly seated on the chair on which the pressure detection sensor in which 60 taxels are arranged in a matrix is placed, it is shown in FIGS. 13 (a) and 13 (b). Thus, although a spectral protrusion was observed in the band of about 0.25 Hz, no spectral protrusion was observed in the band of about 0.8 Hz to about 1.5 Hz. When the results of Example 4 and Comparative Example 6 are summarized, as shown in Table 4, when the subject sits directly on the seat surface of the chair on which the pressure detection sensor is placed, in Example 4, the respiratory component and the heart rate component In contrast, in Comparative Example 6, the heart rate component could not be captured.

  Moreover, although the said embodiment demonstrated the example which measures respiration and a heartbeat as biometric information, this invention is not limited to this, You may measure biometric information (for example, body movement etc.) other than respiration and a heartbeat. .

  Moreover, although the said 1st Embodiment demonstrated the example which arrange | positions a pressure detection sensor in the test subject's chest vicinity position, the position of the pressure detection sensor of this invention is not limited to the test subject's chest vicinity position.

It is the schematic diagram which showed the whole structure of the biological information measuring device which concerns on 1st Embodiment of this invention. It is a schematic diagram of the pressure detection sensor of the biological information measuring device shown in FIG. 3 is a graph showing a frequency spectrum obtained by the biological information measuring apparatus according to Example 1. 6 is a graph showing a frequency spectrum obtained by the biological information measuring apparatus according to Comparative Example 1. 10 is a graph showing a frequency spectrum obtained by the biological information measuring apparatus according to Comparative Example 2. 6 is a graph showing a frequency spectrum obtained by the biological information measuring apparatus according to Example 2. 10 is a graph showing a frequency spectrum obtained by the biological information measuring apparatus according to Comparative Example 3. 10 is a graph showing a frequency spectrum obtained by a biological information measuring apparatus according to Comparative Example 4. It is the schematic diagram which showed the whole structure of the biological information measuring device which concerns on 2nd Embodiment of this invention. 10 is a graph showing a frequency spectrum obtained by the biological information measuring apparatus according to Example 3. 10 is a graph showing a frequency spectrum obtained by a biological information measuring apparatus according to Comparative Example 5. It is the graph which showed the frequency spectrum obtained by the biological information measuring device concerning Example 4. 14 is a graph showing a frequency spectrum obtained by a biological information measuring apparatus according to Comparative Example 6.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1,100 Biological information measuring device 10,110 Pressure detection sensor 11 Metal substrate 12 Piezo element 13 Conductive film 20 Computer 21 Control device 22 Display device 23 Input device

Claims (4)

  Biological information of a subject is measured using a pressure detection sensor provided with a metal substrate and a piezo element that is provided on the metal substrate and whose output voltage changes according to pressure applied from the outside. Information measuring device.   The biological information measuring device according to claim 1, wherein the pressure detection sensor is disposed at a position where the pressure detection sensor does not contact the subject with a lying recumbent member lying therebetween.   The biological information measuring device according to claim 2, wherein the pressure detection sensor is arranged at a position near the chest of the subject lying on the recumbent member.   The biological information measuring device according to claim 1, wherein the pressure detection sensor is disposed at a position where the pressure detection sensor does not contact the subject with a seating member on which the subject sits.

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