JP2004344675A - Body movement detecting apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To detect a man on a mattress wherever he lies on the mattress. <P>SOLUTION: A body movement detecting apparatus has acceleration sensors 10 and 19 to be mounted on bedding and to detect the body movement of the man in the bedding, and a signal terminal part 14 to take out an output signal of the acceleration sensors 10 and 19. In the body movement detecting apparatus, a resonating frequency of the bedding includes frequency regions of respiration and heartbeats of the man in the bedding. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a body motion detection device that detects body motion such as respiration and heartbeat of a sleeping person.

Conventionally, a body movement detecting device of this type generally includes a bed 1 and a piezoelectric member formed of a piezoelectric resin or the like for detecting body movement on the entire upper surface of the mattress 2 as shown in an external view of FIG. Although the sensor 3 is arranged in a meandering manner, the sensor 3 is attached to the bedding by a method in which the sensor 3 is passed through a guide 5 for fixing an arrangement pattern on the surface of the mattress 2 or the sheet 4, and is attached to a Velcro (registered trademark). 6) and the like (for example, see Patent Document 1).
JP-A-3-272744

  However, in the conventional body movement detecting device, the piezoelectric sensor is attached by fixing with a tape for surface bonding, or by forming a tunnel-like passage and passing the piezoelectric sensor through the passage. Considering mass productivity, it is necessary to provide a passage with some allowance in order to pass the piezoelectric sensor, and if the occupant performs a large operation such as turning over while sleeping, the piezoelectric sensor may be displaced or held Floating from members. In addition, when the sheets are laid, if the front surface and the back surface are reversed, there is a problem that the installation state of the piezoelectric sensor changes, and as a result, the sensitivity of the piezoelectric sensor also changes, leading to a decrease in the determination rate of the presence determination. Was.

  Further, for example, when the sensor is stored in three folds or the like, since the bent portion of the sensor is always at the same position, there is a possibility that a failure such as disconnection due to bending may occur.

  Further, when the cushion material holding the piezoelectric sensor is crushed by the weight, there is a problem that the sensitivity is significantly deteriorated.

  In addition, since the acceleration detection area of the piezoelectric sensor is small and cannot be detected unless the piezoelectric sensor is in contact with the human body, especially near the chest, it is necessary to use a piezoelectric sensor so that the person on the mattress can be in any position while sleeping. The sensor must be installed on the entire mattress, which increases the cost of the sensor, and conversely, if a short sensor is used to reduce the cost, the area that can be detected is limited. I was

  Furthermore, when the distance from the human body to the piezoelectric sensor is long, the sensitivity of the piezoelectric sensor itself is low, so that there is a problem that an accurate value is not always obtained for a small body motion component such as heartbeat or respiration. I was

  In order to solve the above-mentioned problems, the present invention has an acceleration sensor arranged on a bedding to detect a body motion of a person on the floor, and a signal terminal unit for extracting an output signal of the acceleration sensor. The frequency range of the floor person's breathing and heartbeat is included, so that the level of vibrations such as breathing and heartbeat with a small excitation level are also attenuated by the bedding, and it is possible to detect a finer body movement level than before. it can.

  Since the body motion detection device of the present invention sets the resonance frequency of the bedding to a region including the frequency range of the occupant's respiration and heartbeat, the detection of minute body motion levels such as the occupant's respiration and heartbeat is detected. Can be easily performed.

  A first invention of the present invention has an acceleration sensor disposed on bedding for detecting a body motion of a person on the bed, and a signal terminal unit for extracting an output signal of the acceleration sensor, wherein the resonance frequency of the bedding is on the bed. This is a body motion detection device that includes the frequency range of the person's breathing and heartbeat. Since the resonance frequency of the bedding falls within the frequency range of the person's breathing and heartbeat, the vibration level is greatly attenuated by the bedding as in the related art. Therefore, it is possible to obtain an output which can be sufficiently detected even with a small body movement.

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

  In each of the embodiments, parts having the same reference numerals have the same structure, and thus a part of the description will be omitted.

(Example 1)
FIG. 1 is an external view of a body motion detection device according to a first embodiment of the present invention. FIG. 2 is a cross-sectional view of a main part of the body motion detection device.

  1 and 2, reference numeral 7 denotes a bed installed in a bedroom or the like, and a bed pad 9 is provided on an upper surface of a mattress 8. Inside the bed pad 9, a flexible cable-shaped acceleration sensor 10 is disposed on a cushion material 11 made of urethane foam, foam rubber, or the like. A quilting process 13 is performed in which the cotton 12 is spread and sewn around the acceleration sensor 10 so that the cotton 12 does not shift. Further, a signal terminal unit 14 for amplifying and extracting an output signal of the acceleration sensor 10 is transmitted to a part of the bed pad 9 and transmitted to a management system (not shown) connected to the signal terminal unit 14 for determining presence of the floor, and a call button or the like. It comprises a transmission unit 15 having a function.

  Although the acceleration sensor 10 has a cable shape, the acceleration sensor 10 can also be implemented in a tape shape.

  Next, the operation will be described. When the occupant lays on the bed pad 9, large body movements such as turning over during bedtime and limb movements are applied to the cable-shaped acceleration sensor 10 through the bed pad 9, but the sewing is sewn around the acceleration sensor 10. Since the quilting process 13 is performed, the acceleration sensor 10 can be prevented from being loosened, biased, or floated from the cushion material 11, can have a stable sensitivity, and can accurately detect the body movement of a sleeping person. , From the transmission unit 15 to the management system. At the same time, the feeling of sleeping is improved.

(Example 2)
FIG. 3 is a sectional view of a main part of a body motion detection device according to a second embodiment of the present invention.

  The difference from the first embodiment is that the cross-sectional structure of the bed pad is symmetrical with the cushion member 11 and the cotton 12 made of the same material as the lower surface and the upper surface around the acceleration sensor 10 in addition to the effects of the first embodiment. When the bed pad 9 is laid on the mattress 8, the same sensitivity can be obtained irrespective of the front and back of the bed pad 9 because the installation state of the acceleration sensor 10 is the same even if the front and back are erroneously mistaken.

(Example 3)
FIG. 4 is a sectional view of a main part of a body motion detection device according to a third embodiment of the present invention.

  The difference from the first embodiment is that a boundary portion 16 of the bed pad 9 between the area A where the acceleration sensor 10 is disposed and the area B where the acceleration sensor 10 is not disposed is formed thin.

  In addition to the effect of the first embodiment, when the bed pad 9 is stored, the bed pad 9 is always folded at the thin boundary portion 16 where the acceleration sensor 10 is not provided. And reliability can be maintained for a long time.

(Example 4)
FIG. 5 is a sectional view of a main part of a body motion detection device according to a fourth embodiment of the present invention.

  The difference from the first embodiment is that the thickness of the cushion material 11 on the lower surface of the acceleration sensor 10 is configured to be smaller than the thickness of the cushion material 11 where the acceleration sensor 10 is not provided, and a space below the cushion material 11 is provided. When the acceleration sensor 10 vibrates due to the body motion of the occupant, the resistance to the movement of the body motion is reduced, and the acceleration sensor 10 is easy to move, and a more sensitive sensor output is obtained. Can be.

(Example 5)
FIG. 6 is an external view of a body motion detection device according to Embodiment 5 of the present invention. FIG. 7 is a sectional view of a main part of the body motion detection device.

  6 and 7, the bed pad 18 includes a cable-shaped acceleration sensor 19, a body movement transmission unit 20, and the cushion material 11. The acceleration sensor 19 is in contact with the body movement transmission unit 20. It is arranged in a direction across the bed 7. The body movement transmitting section 20 is composed of a metal material 21 made of a thin plate of aluminum or a steel plate having a small loss coefficient and an elastic material 22 such as urethane foam having a large elastic modulus on the upper surface thereof.

  Next, the operation and operation will be described. The exciting force due to the body motion of the occupant on the bed pad 18 is applied to the body motion transmission unit 20 and the acceleration sensor 19. For example, even when the occupant's chest is not near the acceleration sensor 19, the elasticity is low. The large elastic material 22 is transmitted to the metal material 21 while maintaining the level of the exciting force, and the vibration transmitted to the metal material 21 is transmitted to the whole body motion transmission unit 20 with a small attenuation since the loss coefficient is small. As a result, the acceleration sensor 19 can sufficiently detect body movement. Therefore, the body movement component can be detected only by disposing the acceleration sensor 19 in a part of the bed pad 18, and the cost can be reduced.

  FIG. 8 is an external view of the body motion detection device in the case where the acceleration sensor 19 is in a tape shape in the fifth embodiment. In this case, the same effect can be obtained.

(Example 6)
FIG. 9 is a sectional view of a main part of a body motion detection device according to a sixth embodiment of the present invention.

  The difference from the fifth embodiment is that a cut-and-raised portion 23 is provided in the metal material 21 constituting the body movement transmitting portion 20.

  Next, the operation will be described. Since the cut-and-raised portion 23 is structurally susceptible to displacement from a force from above, the cut-and-raised portion 23 vibrates due to body movement of the person in bed, and the vibration has a loss coefficient. The small metal material 21 propagates to the entire body motion transmitting unit 20 and is detected by an acceleration sensor 19 provided in contact with the body motion transmitting unit 20. Therefore, the body motion can be transmitted to the acceleration sensor with higher sensitivity to the force from above than in the fifth embodiment.

(Example 7)
FIG. 10 is a sectional view of a main part of a body motion detection device according to a seventh embodiment of the present invention.

  The difference from the fifth embodiment is that the metal material 21 forming the body movement transmitting unit 20 is formed of the corrugated plate 24. The operation is similar to that of the sixth embodiment. Since the metal material 21 having a small loss coefficient has a wavy structure by being applied to the portion 20, the metal material 21 is easily subjected to displacement due to vibration, and as a result, the vibration propagates to the entire body movement transmitting portion 20.

  Therefore, the body motion can be transmitted with higher sensitivity than in the fifth embodiment.

  Although the corrugated plate 24 is used as the metal material 21 in the seventh embodiment, a similar effect can be obtained by providing a portion which is easily displaced, such as applying tension to the film-like material or providing an opening. Can be.

(Example 8)
FIG. 11 is a general characteristic diagram showing a vibration transmissibility for explaining an effect of the eighth embodiment of the present invention. An acceleration sensor 19 for detecting body movement is provided on the bedding, and the body frequency is a body movement detection device in which the resonance frequency is a frequency wrapping the frequency range of the breathing or heartbeat of the occupant. It can be expressed as a vibration system having one degree of freedom. At this time, the resonance frequency is expressed by (Equation 1).

  In FIG. 11, the horizontal axis represents the frequency ratio of the forced external force (body movement of the person in bed) to the natural frequency determined by the entire system (bedding + bed person), and the vertical axis represents the force force of the body (body movement of the person in bed). Level) to the bedding. The difference between the peaks indicates that the difference varies depending on the internal resistance of the bedding including the mattress 8. Therefore, it is necessary to set the resonance frequency of the mattress 8 to the frequency range of respiration and heartbeat in order to actually make it in the resonance region. If the mass M is almost the average weight of an adult human, the spring constant K should be reduced. Can be realized.

  Next, the operation will be described. If the frequency of the whole bedding system including the mattress 8 is set in the resonance region, the forced excitation force on the bedding due to the respiration or heartbeat of the occupant will have a higher transmission rate than before, although there is attenuation due to internal resistance. Since the entire system including the sensor 19 vibrates, a large sensor output is obtained, and a minute body movement can be detected with higher sensitivity. Therefore, there is no need to provide an acceleration sensor that covers the entire bedding.

FIG. 1 is an external view of a body motion detection device according to a first embodiment of the present invention. Sectional view of the main part of the body motion detection device Sectional view of a main part of a body motion detection device according to a second embodiment of the present invention. Sectional view of a main part of a body motion detection device according to a third embodiment of the present invention. Sectional view of a main part of a body motion detection device according to a fourth embodiment of the present invention. 5 is an external view of a body motion detection device according to a fifth embodiment of the present invention. Sectional view of the main part of the body motion detection device External view showing another example of the body motion detection device Sectional view of a main part of a body motion detection device according to a sixth embodiment of the present invention. Sectional view of a main part of a body motion detection device according to a seventh embodiment of the present invention. A general characteristic diagram showing a vibration transmissibility for explaining an effect of the eighth embodiment of the present invention. External view of conventional body motion detection device

Explanation of reference numerals

Reference Signs List 8 Mattress 9, 18 Bed pad 10, 19 Acceleration sensor 11 Cushion material 12 Cotton 13 Quilting process 14 Signal terminal portion 16 Boundary portion 17 Space portion 20 Body movement transmitting portion 21 Metal material 22 Elastic material 23 Cut-and-raised portion 24 Corrugated plate

Claims (1)

An acceleration sensor disposed on the bedding and detecting a body motion of the occupant; and a signal terminal unit for extracting an output signal of the acceleration sensor, wherein the resonance frequency of the bedding corresponds to the frequency range of respiration and heartbeat of the occupant. Body motion detection device including.

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