JP3953056B2 - Body motion detection device - Google Patents

Description

  The present invention relates to a body motion detection device that detects body motion such as breathing and heartbeat of a human body.

Conventionally, this kind of body motion detecting device is generally a piezoelectric material formed on the entire upper surface of the mattress 2 from a piezoelectric resin or the like for detecting body motion, as shown in FIG. Although the sensor 3 is arranged in a meandering manner, the attachment to the bedding is performed by passing it through a guide 5 that fixes the arrangement pattern on the surface of the mattress 2 or the sheet 4, and this is applied to the magic tape (registered trademark). 6) etc. (for example, refer patent document 1).
JP-A-3-272744

  However, in the conventional body motion detection device, the piezoelectric sensor is attached by fixing it with a tape for surface adhesion, or by forming a tunnel-shaped passage and passing the piezoelectric sensor through it. Considering mass productivity, it is necessary to provide a passage with a certain amount of room to pass through the piezoelectric sensor, and if the bedridden person performs a large action such as turning over while sleeping, the piezoelectric sensor may be displaced or held from the installation position. It floats from the member. In addition, when the sheets are laid, if the front and back surfaces are reversed, 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 floor presence. It was.

  For example, when the sensor is stored in a tri-fold, the sensor is always bent at the same position, which may cause a failure such as disconnection due to the bending.

  In addition, when the cushion material holding the piezoelectric sensor is crushed by weight, the sensitivity is greatly deteriorated.

  In addition, since the acceleration detection area of the piezoelectric sensor is small and it cannot be detected unless the piezoelectric sensor is in contact with the human body, particularly in the vicinity of the chest, the piezoelectric sensor can be used to detect where a person on the mattress is sleeping. The sensor must be disposed on the entire mattress, resulting in an increase in the cost of the sensor, and conversely, if a short sensor is used to reduce the cost, there is a problem that the area that can be detected is limited. It was.

  Furthermore, when the distance from the human body to the piezoelectric sensor is increased, the sensitivity of the piezoelectric sensor itself is small, and thus there is a problem that an accurate value cannot always be obtained for small body motion components such as heartbeat and respiration. It was.

  In order to solve the above problems, the present invention includes an acceleration sensor for detecting body motion of a human body, a body motion transmission unit made of a material having a large elastic modulus and a small loss coefficient, and a signal terminal unit for taking out an output signal of the acceleration sensor. A body motion detecting device having a pad arranged so as to be in contact with the body motion transmitting portion, and the body motion transmitting portion having a large elastic modulus and a small loss coefficient is in contact with the acceleration sensor. Even if there is a vibration source such as the chest away from the sensor position, vibration can be efficiently transmitted to the sensor side, and even if the entire pad is not covered with the acceleration sensor, only an acceleration sensor is provided on a part of the pad. A wide range of body movements can be detected.

  In the body motion detection device of the present invention, the pad is provided with a body motion transmitting portion having a large elastic modulus and a small loss coefficient, and an acceleration sensor is disposed so as to contact the body motion detecting portion, so that a vibration source such as a chest is located at a position away from the position of the acceleration sensor. Even in such a case, the vibration is efficiently propagated to the acceleration sensor, so that it is possible to detect a wide range of body motion components and to reduce the cost only by providing a part of the sensor on the pad.

  The first invention of the present invention has an acceleration sensor for detecting body motion of a human body, a body motion transmission unit made of a material having a large elastic modulus and a small loss coefficient, and a signal terminal unit for taking out an output signal of the acceleration sensor. And a body motion detecting device having a pad arranged so that the acceleration sensor is in contact with the body motion transmitting portion, and the body motion transmitting portion having a large elastic modulus and a small loss coefficient is in contact with the acceleration sensor. Even if there is a vibration source such as the chest away from the position, vibration can be efficiently transmitted to the sensor side, and even if the entire pad is not covered with the acceleration sensor, only an acceleration sensor is provided on a part of the pad. A wide range of body movements can be detected.

  Further, the second invention of the present invention is that the body motion transmission part is made of a metal material having a cut-and-raised part and an elastic material, and the cut-and-raised part is susceptible to displacement with respect to the force from the upper side. Vibration due to body movement is also large, and the body movement of the human body can be transmitted to the acceleration sensor with higher sensitivity.

  According to a third aspect of the present invention, the body motion transmitting portion is made of a corrugated metal material and an elastic material, and the structure of the thin corrugated plate is susceptible to displacement due to vibration. It propagates to the entire transmission part and can be detected with high sensitivity by the acceleration sensor.

  Embodiments of the present invention will be described below with reference to the drawings.

  In addition, in each Example, since the thing of the same code | symbol has the same structure, description is abbreviate | omitted partially.

Example 1
FIG. 1 is an external view of a body movement detection apparatus according to a first embodiment of the present invention. FIG. 2 is a cross-sectional view of the 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 the upper surface of the mattress 8. Inside the bed pad 9, a flexible cable-like acceleration sensor 10 is disposed on a cushion material 11 made of urethane foam, foam rubber, or the like, and the upper surface including the location where the acceleration sensor 10 is disposed is cotton. A quilting process 13 is performed by sewing around the acceleration sensor 10 so that the cotton 12 is not displaced. Also, a signal terminal unit 14 that amplifies the output signal of the acceleration sensor 10 to a part of the bed pad 9 and a management system (not shown) that is connected to the signal terminal unit 14 to determine the presence of the floor are transmitted to The transmission unit 15 has a function.

  Although the acceleration sensor 10 has a cable shape, the present invention can be similarly applied to a tape shape.

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

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

  The difference from the first embodiment is that the cross-sectional structure of the bed pad is configured symmetrically with the cushioning material 11 and the cotton 12 made of the same material as the upper and lower surfaces 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 regardless 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 mistaken.

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

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

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

Example 4
FIG. 5 is a cross-sectional view of a main part of the body movement detection device according to the 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 made thinner than the thickness of the cushion material 11 on which the acceleration sensor 10 is not disposed, and a space is provided below the cushion material 11. In other words, when the acceleration sensor 10 vibrates due to the body movement of the person in the bed, the resistance to the movement of the body movement becomes small, the acceleration sensor 10 is easy to move, and a more sensitive sensor output is obtained. Can do.

(Example 5)
FIG. 6 is an external view of a body movement detecting apparatus according to Embodiment 5 of the present invention. FIG. 7 is a cross-sectional view of a main part of the same body motion detecting device.

  6 and 7, the bed pad 18 includes a cable-like acceleration sensor 19, a body motion transmission unit 20, and a cushion material 11, and only one acceleration sensor 19 is in contact with the body motion transmission unit 20. It is arranged in a direction across the bed 7. The body motion transmitting portion 20 is composed of a metal material 21 made of aluminum or a thin 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 action will be described. The excitation force due to the body motion of the bed person on the bed pad 18 is applied to the body movement transmitting unit 20 and the acceleration sensor 19. For example, even when the bed person's chest is not in the vicinity of the acceleration sensor 19, the elastic modulus is high. The large elastic material 22 maintains the level of the excitation force and transmits it to the metal material 21, and the vibration transmitted to the metal material 21 has a small loss coefficient and propagates to the entire body motion transmission unit 20 with a slight attenuation. As a result, the acceleration sensor 19 can sufficiently detect body movement. Therefore, it is possible to detect the body motion component by simply disposing the acceleration sensor 19 in a part of the bed pad 18, and the cost can be reduced.

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

(Example 6)
FIG. 9 is a cross-sectional view of a main part of a body movement detecting apparatus according to Embodiment 6 of the present invention.

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

  Next, the operation will be described. Since the cut-and-raised part 23 is structurally susceptible to displacement with respect to the force from the upper side, the cut-and-raised part 23 vibrates due to the body movement of the in-person, 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 the acceleration sensor 19 provided in contact with the body motion transmitting unit 20. Therefore, the body movement can be transmitted to the acceleration sensor with higher sensitivity than the fifth embodiment with respect to the force from above.

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

  The difference from the fifth embodiment is that the metal material 21 constituting the body motion transmitting unit 20 is configured by the corrugated plate 24. As for the action, the body motion of the in-bed person is transmitted by the body motion as in the sixth embodiment. Since the metal material 21 having a small loss coefficient has a wave-like structure by being added to the portion 20, the metal material 21 is easily subjected to displacement with respect to vibration, and as a result, the vibration propagates to the entire body motion transmitting portion 20.

  Therefore, the body movement can be propagated with higher sensitivity than in the fifth embodiment.

  In addition, although the metal material 21 is the corrugated plate 24 in the seventh embodiment, the same effect can be obtained by providing a portion that is susceptible to displacement, such as applying tension to the film-like material or providing an opening. Can do.

(Example 8)
FIG. 11 is a general characteristic diagram showing the vibration transmissibility for explaining the effect of the eighth embodiment of the present invention. The body motion detection device is provided with an acceleration sensor 19 for detecting body motion on the bedding, and the resonance frequency is a frequency for wrapping the frequency range of breathing and heartbeat of the occupant. Although it can be expressed as a vibration system with one degree of freedom, the resonance frequency is expressed by (Equation 1).

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

  Next, the operation will be described. When the frequency of the entire system of the bedding including the mattress 8 is set in the resonance region, the forced excitation force applied to the bedclothes due to the breathing and heartbeat of the occupant is attenuated by internal resistance, but the transmission rate is larger than the conventional one. The entire system including the sensor 19 vibrates and a large sensor output is obtained, so that minute body movement can be detected with higher sensitivity. Therefore, it is not necessary to provide an acceleration sensor that covers the entire bedding.

1 is an external view of a body motion detection device according to a first embodiment of the present invention. Cross section of the main part of the body motion detection device Sectional drawing of the principal part of the body movement detection apparatus of Example 2 of this invention Sectional drawing of the principal part of the body movement detection apparatus of Example 3 of this invention Sectional drawing of the principal part of the body movement detection apparatus of Example 4 of this invention External view of body movement detection apparatus of Embodiment 5 of the present invention Cross section of the main part of the body motion detection device External view showing other examples of body motion detection devices Sectional drawing of the principal part of the body movement detection apparatus of Example 6 of this invention Sectional drawing of the principal part of the body movement detection apparatus of Example 7 of this invention General characteristic diagram showing vibration transmissibility for explaining the effect of the eighth embodiment of the present invention External view of conventional body motion detection device

Explanation of symbols

8 Mattress 9, 18 Bed pad 10, 19 Acceleration sensor 11 Cushion material 12 Cotton 13 Quilting 14 Signal terminal part 16 Boundary part 17 Space part 20 Body motion transmitting part 21 Metal material 22 Elastic material 23 Cut-and-raised part 24 Wave plate

Claims (2)

An acceleration sensor for detecting body motion of a human body, a body motion transmission unit made of a material having a large elastic modulus and a small loss coefficient, and a signal terminal unit for taking out an output signal of the acceleration sensor; A body motion detection device having a pad disposed so as to be in contact with a transmission portion, wherein the body motion transmission portion is formed of a metal material having a cut-and-raised portion and an elastic material. An acceleration sensor for detecting body motion of a human body, a body motion transmission unit made of a material having a large elastic modulus and a small loss coefficient, and a signal terminal unit for taking out an output signal of the acceleration sensor; A body motion detection device having a pad disposed so as to be in contact with a transmission portion, wherein the body motion transmission portion is made of a corrugated metal material and an elastic material .

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