JP5495952B2 - Biological monitoring device - Google Patents

Description

  The present invention relates to a biological monitoring apparatus that detects a subject's movement and vibration and monitors, for example, apnea and cardiac arrest.

In recent years, sudden death syndrome of newborn infants that occur during sleep and apnea syndrome of adults are increasing.For early detection of these symptoms, body movements including breathing can be performed without attaching a detection device directly to the body. Devices that can be measured have been proposed.
For example, in Patent Document 1, a detection mat having a pressure-sensitive pipe, a pressure measuring unit that measures a pressure inside the pressure-sensitive pipe at a predetermined time by a pressure sensor unit, and a signal received from the pressure measuring unit are sensed. An apnea detection device comprising an apnea detection means for detecting an apnea state from the pressure change of the pressure pipe, and laying the subject on the detection mat allows breathing without wearing any cords or sensors. There is one that can detect apnea by reliably measuring body movement including respiration of the subject.
Further, in Patent Document 2, a body movement measuring unit that detects a dynamic signal based on biological vibration connected to an integrated sensor sheet and a body pressure measuring unit that detects a static signal based on body pressure of the living body are provided. Some of them obtain biological signals such as body weight, heart rate, respiration, activity, and life state by synthesizing their outputs.
In Patent Document 3, a heartbeat / respiration sensor is configured by a flexible vibration transmission plate in which a plurality of air holes are formed and a piezoelectric transducer attached to the vibration transmission plate. According to this configuration, the vibration transmission plate is vibrated by the heart sound or breathing sound of the subject, and the vibration is transmitted to the piezoelectric transducer. Therefore, even when the sensor is installed on a soft futon, And respiration can be detected with high sensitivity.
Moreover, in patent document 4, a pair of plate-shaped member is provided in the opposing surface of the piezoelectric crystal converter. The pair of plate members are larger in diameter than the piezoelectric crystal transducer and are made of a relatively hard material, which are joined at the outer periphery, and the transducer is centered between them. .
Moreover, in patent document 5, it has a flexible vibration transmission board with which the sensor was attached to the center part of the back surface side by the adhesive agent etc., and a support plate which supports a vibration transmission board via several spacers. ing. The vibration transmission plate is made of a thin sheet-like member made of plastic resin or metal, and a piezoelectric element or a polymer piezoelectric element film sensor made of, for example, piezoceramic is used as the sensor.

JP 2000-107154 A JP-A-10-14889 JP 2006-129933 A JP-A-5-176898 International Publication 2007/029326

According to Patent Literature 1, vibration due to respiration can be reliably detected, but since a pressure change caused by a pressure-sensitive pipe is used, it is difficult to detect even a heartbeat vibration that is a slight vibration compared to respiration. . In addition, since the position of the subject is deviated from the position of the pressure-sensitive pipe, it becomes difficult to detect vibration.
According to Patent Document 2, the sensor sheet is configured to detect heartbeat and respiration by being compressed, and can be detected with extremely high sensitivity when the sensor sheet is installed on a hard material. However, sufficient detection cannot be performed under the conditions of the installation location with the futon laid under the sensor sheet.
According to Patent Document 3, by providing a vibration transmission plate having flexibility, it is possible to detect movement by turning the subject upside down as compared with the case where the piezoelectric transducer is used alone. It is still affected by the conditions of the installation location, and furthermore, the vibration transmission plate is formed with a large number of air holes, making it difficult for vibration to be transmitted, and the effect of displacement between the subject and the piezoelectric transducer Is big.
According to Patent Document 4, since a piezoelectric crystal converter is provided between a pair of plate-like members, it is difficult to be affected by the conditions of the installation location, but the upper plate serving as a mounting surface swells in a convex shape. Therefore, the subject is likely to be displaced from the center of the plate, and the vibration is difficult to detect due to the displacement of the subject.
Since Patent Document 5 targets small animals that are much lighter than the subject, the vibration transmission plate is supported by spacers at the four corners and the center. In particular, the spacer for preventing the deflection at the center of the vibration transmitting plate is formed in a conical shape to suppress vibration attenuation. Therefore, if it is applied to a subject, it is considered that it is less affected by the conditions of the installation location because it has a support plate. However, when the subject deviates from the center of the plate or has an adverse effect on vibration detection by the central spacer. Must be eliminated.

  Therefore, an object of the present invention is to provide a living body monitoring apparatus that can detect even a slight body movement such as heartbeat vibration and can reliably detect vibration even when the placement position of a subject is shifted.

The living body monitoring apparatus according to the first aspect of the present invention forms a space between a resonance plate on which a subject is placed, a polymer piezoelectric element film sensor attached to a lower surface of the resonance plate, and the resonance plate. A living body monitoring device for detecting vibration of at least one of heartbeat and breathing of the subject, wherein the lower case is configured in a dome shape whose center is farther from the resonance plate than the four corners. Features.
According to a second aspect of the present invention, in the living body monitoring device according to the first aspect, the first load necessary for deforming the center of the lower case toward the resonance plate by a predetermined amount is the resonance plate. The rigidity of the lower case is made higher than the rigidity of the resonance plate so as to be larger than a second load required to deform the center toward the lower case by a predetermined amount.
According to a third aspect of the present invention, in the living body monitoring apparatus according to the first or second aspect, the resonance plate and the lower case are each composed of a pair of short sides and a pair of long sides, and the resonance The plate and the lower case are in contact with each other at the four corners, and the resonance plate and the lower case have gaps other than the four corners.
According to a fourth aspect of the present invention, in the living body monitoring device according to any one of the first to third aspects, the lower case includes a first rib extending in a diagonal direction and the long side. And a second rib extending in the direction.
According to a fifth aspect of the present invention, in the living body monitoring apparatus according to any one of the first to fourth aspects, an elastic material is provided at the center of the lower case, and the height of the elastic material is set to the height. The rib is higher than the rib adjacent to the elastic material, and there is a gap between the elastic material and the polymer piezoelectric element film sensor in a no-load state.
According to a sixth aspect of the present invention, in the living body monitoring device according to any one of the first to fifth aspects, a plastic corrugated board is used as the resonance plate, and the vertical board constituting the corrugated board is used. It is characterized by the direction of the long side being the direction of the long side.
According to a seventh aspect of the present invention, in the living body monitoring apparatus according to any one of the first to sixth aspects, a conductive film is formed on the resonance plate, or the resonance plate includes a conductive material. It is characterized by molding.

  According to the present invention, a polymer piezoelectric element film sensor is used, and this polymer piezoelectric element film sensor is attached to the lower surface of the resonance plate to detect slight vibration such as heartbeat vibration. In addition, since the lower case has a dome shape, when the subject leans on one side due to turning over, etc., the other floats, so that the vibration from the subject can be reliably transmitted to the resonance plate, and the polymer An electromotive force due to vibration can be obtained by the piezoelectric element film sensor.

The top view of the biological monitoring apparatus in one Embodiment of this invention AA line sectional view of FIG. BB sectional view of FIG. Top view of the lower case of the biological monitoring device Perspective view of the lower case The figure which shows the use condition in the scheduled normal state of the biological monitoring apparatus in this embodiment. The figure which shows the use condition in the state which the test subject of the biological monitoring apparatus in this embodiment turned over. The figure which shows the use condition in case the test subject's weight of the biological monitoring apparatus in this embodiment is light. The figure which shows the use condition in case the test subject's weight of the biological monitoring apparatus in this embodiment is heavy. The figure which shows the result of the sensitivity test classified by load of the biological monitoring apparatus in this embodiment The figure which shows the result of the rigidity test of the resonance board and lower case of the biological monitoring apparatus in this embodiment

The living body monitoring apparatus according to the first embodiment of the present invention forms a space between a resonance plate on which a subject is placed, a polymer piezoelectric element film sensor attached to the lower surface of the resonance plate, and the resonance plate. A living body monitoring apparatus that includes a lower case and detects vibrations of at least one of heartbeat and respiration of a subject, and the lower case is configured in a dome shape with the center farther from the resonance plate than the four corners. According to the present embodiment, a polymer piezoelectric element film sensor is used, and this polymer piezoelectric element film sensor is attached to the lower surface of the resonance plate to detect slight vibration such as heartbeat vibration. In addition, since the lower case has a dome shape, when the subject leans on one side by turning over, etc., the other is lifted, so that the vibration from the subject can be reliably transmitted to the resonance plate, An electromotive force due to vibration can be obtained by the polymer piezoelectric element film sensor.
According to the second embodiment of the present invention, in the living body monitoring apparatus according to the first embodiment, the first load necessary for deforming the center of the lower case by a predetermined amount toward the resonance plate is the center of the resonance plate. The rigidity of the lower case is made higher than the rigidity of the resonance plate so as to be larger than the second load necessary for deforming a predetermined amount toward the lower case side. According to the present embodiment, the resonance plate can be bent, and the dome shape of the lower case is maintained, so that vibration from the subject can be reliably obtained by the resonance plate.
According to a third embodiment of the present invention, in the living body monitoring apparatus according to the first or second embodiment, the resonance plate and the lower case are each configured by a pair of short sides and a pair of long sides, and the resonance plate And the lower case are in contact with each other at the four corners, and there is a gap between the resonance plate and the lower case except for the four corners. According to the present embodiment, it is possible to deal with a wide range of weights by balancing tension at the four corners.
According to a fourth embodiment of the present invention, in the living body monitoring apparatus according to the first to third embodiments, the lower case includes a first rib extending in the diagonal direction and a second side extending in the long side direction. And ribs. According to the present embodiment, it is possible to maintain the dome shape by increasing the rigidity particularly in the diagonal direction and the longitudinal direction.
According to a fifth embodiment of the present invention, in the living body monitoring apparatus according to the first to fourth embodiments, an elastic material is provided in the center of the lower case, and the height of the elastic material is set higher than that of the rib close to the elastic material. In the no-load state, there is a gap between the elastic material and the polymer piezoelectric element film sensor. According to the present embodiment, until the polymer piezoelectric element film sensor comes into contact with the elastic material, the tensile stress acts on the resonance plate due to the body weight of the subject, and the polymer piezoelectric element film sensor comes into contact with the elastic material. Later, distortion due to the Poisson effect is added, so that it is possible to detect vibrations over a wide range of weights by enabling two-stage detection.
According to a sixth embodiment of the present invention, in the living body monitoring apparatus according to the first to fifth embodiments, a plastic corrugated board is used as the resonance plate, and the streaks of the vertical board constituting the corrugated board are long. This is the direction. According to the present embodiment, the rigidity in the long side direction is excellent, and ultra-low frequency resonance can be obtained.
The seventh embodiment of the present invention is a living body monitoring apparatus according to the first to sixth embodiments, in which a conductive film is formed on a resonance plate, or a resonance plate is molded containing a conductive material. is there. According to this embodiment, generation of static electricity can be prevented and the influence of noise can be removed.

Hereinafter, an embodiment of the biological monitoring apparatus of the present invention will be described.
1 is a plan view of a living body monitoring apparatus according to an embodiment of the present invention, FIG. 2 is a sectional view taken along line AA in FIG. 1, FIG. 3 is a sectional view taken along line BB in FIG. FIG. 5 is a perspective view of the lower case.
The biological monitoring apparatus according to the present embodiment is a lower case that forms a space between the resonance plate 10 on which the subject is placed, the polymer piezoelectric element film sensor 20 that is attached to the lower surface of the resonance plate 10, and the resonance plate 10. 30, and can detect the body movement of the subject, particularly vibrations caused by breathing and heartbeat vibrations.

For the resonance plate 10, for example, a plastic corrugated board such as polypropylene is used. Therefore, the resonance plate 10 constitutes a corrugated board by the hollow structure of the front plate 11, the vertical plate 12 and the back plate 13. As shown in FIG. 2, the vertical plate 12 has a ladder-like cross section, and has a continuous structure that is lightweight and has a pressing strength.
The resonant plate 10 is composed of a pair of short sides and a pair of long sides, and has four corners configured in an arc shape.
The lines of the vertical plate 12 are in the direction of the long side of the resonance plate 10. Further, it is preferable to form a conductive film on the resonance plate 10 or to mold the resonance plate 10 including a conductive material.
As the polymer piezoelectric element film sensor 20, one using polyvinylidene fluoride as a polymer material is known. The polymer piezoelectric element film sensor 20 is affixed to the lower surface of the center of the resonance plate 10, and generates an electromotive force due to a tensile stress acting due to load deflection generated in the resonance plate 10.
As shown in FIG. 1, the polymer piezoelectric element film sensor 20 is provided with a lead wire 21.

The lower case 30 includes a pair of short sides and a pair of long sides, and has four corners formed in an arc shape. The lower case 30 is vacuum-formed using polystyrene, and has a dome shape in which the center is farther from the resonance plate 10 than the four corners. Therefore, as shown in FIGS. 2 and 3, the lower case 30 is in a state where both sides are lifted from the installation surface X in a state where the lower case 30 is in contact with the installation surface X at the center.
The resonant plate 10 and the lower case 30 are in contact with each other at the four corners (broken line positions in FIG. 1), and there are gaps between the resonant plate 10 and the lower case 30 except for the four corners.

As shown in FIGS. 3 and 4, the lower case 30 has a first rib 31 extending in a diagonal direction from the center toward the four corners, a second rib 32 extending in the long side direction, and a short side. And a third rib 33 extending in the direction. Center-side end portions of the pair of first ribs 31 are continuous by the second ribs 32. Further, the end portions of the second rib 32 and the third rib 33 located on the outer periphery of the lower case 30 are continuous. The ribs 31, 32, and 33 are configured by grooves that protrude from the back surface of the lower case 30 toward the surface.
As shown in FIGS. 2 to 5, an elastic material 40 is provided at the center of the lower case 30. The height of the elastic material 40 is higher than that of the second rib 32 closest to the elastic material 40, and a gap is provided between the elastic material 40 and the polymer piezoelectric element film sensor 20 when the resonance plate 10 is not loaded. Provided.

Next, the use state of the biological monitoring apparatus in this embodiment will be described.
FIG. 6 is a diagram showing a usage situation in a planned normal state, and FIG. 7 is a diagram showing a usage situation in a state where the subject has turned over.
In the figure, the living body monitoring apparatus in the present embodiment shows a state of being placed on an installation surface X such as a bed or a floor surface, and a subject Y is placed thereon.
Since the resonance plate 10 is supported in contact with the lower case 30 at the four corners as described above, even if the placement surface X is a futon or the like instead of the hard placement surface X as shown in the drawing, Can be accurately transmitted to the resonance plate 10.
Further, as shown in FIG. 7, when the subject Y leans to one side due to turning over or the like, the other is lifted, so that vibration from the subject Y can be reliably transmitted to the resonance plate 10.

FIG. 8 is a diagram showing a usage situation when the subject's weight is light, and FIG. 9 is a diagram showing a usage situation when the subject's weight is heavy.
As shown in FIG. 8, when the weight of the subject Y is light, the polymer piezoelectric element film sensor 20 does not come into contact with the elastic material 40. Therefore, a tensile stress acts on the resonance plate 10 due to the weight deflection of the subject Y. In this state, vibration due to breathing or heartbeat can be detected by stress fluctuation.
As shown in FIG. 9, when the weight of the subject Y is heavy, the polymer piezoelectric element film sensor 20 is in contact with the elastic material 40, and a tensile stress acts on the resonance plate 10 due to the body weight of the subject Y. Further, distortion due to the Poisson effect due to the polymer piezoelectric element film sensor 20 being pressed by the elastic material 40 is added, and in this state, vibration due to breathing or heartbeat can be detected by stress fluctuation.

FIG. 10 shows the result of the sensitivity test according to load of the biological monitoring apparatus in the present embodiment.
In this test, a 3 mm, 4 mm, and 5 mm polypropylene plastic corrugated board having a thickness of 3 mm, 4 mm, and 5 mm was used as the resonance plate 10, and a dome-shaped molded product having a thickness of 4 mm that was vacuum molded using polystyrene as the lower case 30. The lines of the vertical plate 12 in the resonant plate 10 are in the direction of the long side of the resonant plate 10.
The load output was set to 0.5 kg to 10.5 kg, and the amplifier output value (mV) at each load load was measured. A resonance plate having a thickness of 3 mm is referred to as Example 1, a resonance plate having a thickness of 4 mm is referred to as Example 2, and a resonance plate having a thickness of 5 mm is referred to as Example 3.
In Example 1, for a load of 0.5 kg to 5.0 kg, in Example 2 to a range of 0.5 kg to 6.5 kg, and in Example 3 to a load of 0.5 kg to 6.0 kg. Good sensitivity could be obtained.
In Example 1, 0.5 kg and 4.0 kg, in Example 2, 1.0 kg and 4.5 kg, and in Example 3, 1.0 kg and 4.0 kg, particularly good sensitivity can be obtained. In this embodiment, it was found that by enabling two-stage detection, two sensitive peaks can be obtained, and vibration detection for a wide range of weights can be performed.

As described above, when the plate thickness of the resonance plate 10 was 3 mm to 5 mm, good electromotive force was generated from the polymer piezoelectric element film sensor 20.
In the sensitivity test, as a comparative example 1, a polypropylene plate (3 mm) was used as a resonance plate, and as a comparative example 2, a polypropylene plastic in which the streaks of the vertical plate 12 were in the direction of the short side of the resonance plate 10. When an experiment was performed using a corrugated cardboard plate (3 mm) made as a resonance plate, vibrations interfered with each other, resulting in an output different from that caused by breathing or heartbeat.

FIG. 11 shows the result of a rigidity test between the resonance plate and the lower case of the living body monitoring apparatus in the present embodiment.
Examples 1 to 3 in the same test are the same samples as described in FIG.
As shown in FIG. 11, the first load B necessary for deforming the center of the lower case 30 toward the resonance plate 10 by a predetermined amount causes the center of the resonance plate 10 to deform toward the lower case 30 by a predetermined amount. The rigidity of the lower case 30 is made higher than the rigidity of the resonance plate 10 so as to be larger than the necessary second load A.

As described above, according to the present embodiment, the polymer piezoelectric element film sensor 20 is used, and the polymer piezoelectric element film sensor 20 is attached to the lower surface of the resonance plate 10 so that the heartbeat vibration or the like can be obtained. Slight vibrations can be detected, and furthermore, since the lower case 30 has a dome shape, when the subject Y leans to one side due to turning over or the like, the other is lifted, so the vibration from the subject Y resonates. It can be reliably transmitted to the plate 10, and an electromotive force due to vibration can be obtained by the polymer piezoelectric element film sensor 20.
Further, according to the present embodiment, the first load B necessary for deforming the center of the lower case 30 toward the resonance plate 10 side by a predetermined amount causes the center of the resonance plate 10 to deform by a predetermined amount toward the lower case 30 side. Since the rigidity of the lower case 30 is made higher than the rigidity of the resonance plate 10 so as to be larger than the second load A required for the resonance, the resonance plate 10 can be bent and the dome shape of the lower case 30 can be obtained. Therefore, vibration from the subject Y can be reliably obtained by the resonance plate 10.
Further, according to the present embodiment, the resonant plate 10 and the lower case 30 are each configured by a pair of short sides and a pair of long sides, and the four corners of the resonant plate 10 and the lower case 30 are configured in an arc shape, Since the resonance plate 10 and the lower case 30 are in contact with each other at the four corners, and the resonance plate 10 and the lower case 30 have a gap at the corners other than the four corners, it is possible to cope with a wide range of weight by balancing the tension at the four corners. .
Further, according to the present embodiment, the lower case 30 includes the first ribs 31 extending in the diagonal direction and the second ribs 32 extending in the long side direction, and particularly in the diagonal direction and the longitudinal direction. Rigidity can be increased and the dome shape can be maintained.
Further, according to the present embodiment, the elastic member 40 is provided in the center of the lower case 30, and the height of the elastic member 40 is made higher than that of the second rib 32 adjacent to the elastic member 40, and the elastic member 40 is in an unloaded state. 40 and the polymer piezoelectric element film sensor 20 are provided with a gap, and until the polymer piezoelectric element film sensor 20 comes into contact with the elastic member 40, the tensile stress is applied to the resonance plate 10 due to the weight of the subject Y. Since the strain due to the Poisson effect is added after the polymer piezoelectric element film sensor 20 comes into contact with the elastic material 40, it is possible to detect vibrations over a wide range of weights by enabling two-stage detection. .
Further, according to the present embodiment, a plastic corrugated board is used as the resonance plate 10, and the streaks of the vertical board 12 constituting the corrugated board are set in the direction of the long side, so that the rigidity in the long side direction is excellent, Ultra-low frequency resonance can be obtained.
Moreover, according to this embodiment, by forming a conductive film on the resonance plate 10 or molding the resonance plate 10 including a conductive material, generation of static electricity can be prevented and the influence of noise can be removed.

  As described above, according to the present embodiment, it is possible to provide a living body monitoring device that can detect apnea and heartbeat stop early.

DESCRIPTION OF SYMBOLS 10 Resonant plate 20 Polymer piezoelectric element film sensor 30 Lower case 31 1st rib 32 2nd rib 40 Elastic material

Claims (7)

  A resonance plate on which the subject is placed, a polymer piezoelectric element film sensor attached to the lower surface of the resonance plate, and a lower case that forms a space between the resonance plate, and the heart rate and breathing of the subject A living body monitoring apparatus for detecting at least one of the vibrations, wherein the lower case is configured in a dome shape whose center is farther from the resonance plate than the four corners.   A first load required to deform the center of the lower case toward the resonance plate by a predetermined amount is a second load necessary to deform the center of the resonance plate toward the lower case by a predetermined amount. The living body monitoring apparatus according to claim 1, wherein the rigidity of the lower case is made higher than the rigidity of the resonance plate so as to be larger.   The resonance plate and the lower case are each composed of a pair of short sides and a pair of long sides, and the resonance plate and the lower case are in contact with each other at the four corners, and the resonance plate and the lower case are other than the four corners. The living body monitoring apparatus according to claim 1, wherein the living body monitoring apparatus has a gap with the case. The said lower case, and a first rib extending diagonally of the direction, according to any one of claims 1 to 3, characterized in that a second rib extending in the direction of the long side Biological monitoring device. An elastic material is provided at the center of the lower case so that the height of the elastic material is higher than that of the rib adjacent to the elastic material, and between the elastic material and the polymer piezoelectric element film sensor in an unloaded state. biological monitoring device according to any one of claims 1 to 4, characterized in that a gap in the. As the resonant plate, using a plastic cardboard plate, according to any one of claims 1 to 5, characterized in that the direction of the long side of the streaks of the vertical plates constituting the corrugated cardboard plate Biological monitoring device. Wherein forming a conductive film on the resonance plate, or biological monitoring device according to contain a conductive material that has been molded the resonant plate of claims 1, wherein any one of claims 6.