JP2001037821A - Sensor device of bed and bed using it - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a durable and reliable means capable of saving cost for monitoring an occupant by arranging a sensor device so as to deflect downward by body weight of a bed occupant and apply pressure to a sensor even when the body weight rests on an upper side member in a position different from a sensor position. SOLUTION: In a sensor unit 2, plates 4 and 6 having upper side and lower side thin and hard steel plates are respectively a rectangular shape, have side parts 12 and 14, and are mutually parallelly positioned in a short side peripheral part by leaving a space between mutual ones by cross-sectional square metallic bars (spacers) 8 and 10. When the hard upper plate 4 substantially deflects, the upper plate becomes a shallow U shape over the whole width. A point (contact) sensor is arranged in a central position between both plates 4 and 6, desirably, in a geometrical central position between both to detect central vertical directional operation of the plate 4 or a steel sheet. A signal from the sensor 16 is sent to a control unit via a sensor cable 18.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sensor device structure, and more particularly, to a bed mainly used for those who are in poor health or weakness and need to monitor for their physical condition. For a sensor device for The present invention also relates to a bed using the sensor device.

[0002] The sensor device according to the present invention is used in a bed used by a person to be monitored, but the sensor device is not strictly defined as a bed as long as it accepts the person to be monitored. It should be pointed out that it is also used for such articles.

[0003]

BACKGROUND OF THE INVENTION Various arrangements for monitoring occupancy of beds have been proposed in various patent specifications.

For example, US Pat. No. 4,484,043 proposes a weight-responsive switch device in the form of a flexible, long sensor. The sensor consists of two flexible sheets bonded to a motorized layer, the conductive layers being spaced apart from each other by an electrically insulating foamable support frame.
The sensor is positioned across the mattress, the patient is lying on the sensor, and an electrical contact is made between the conductive layers. When the patient leaves or falls off the bed, the contact is broken and an alarm is activated, signaling that the patient is in danger. However, this device is relatively fragile and substantially disposable and must be replaced on a monthly basis due to wear and tear.

[0005] Another earlier proposal is disclosed in US Patent No. 4,295,133.
This is a pair of parallel curved strips that are mounted so that they remain parallel when flexed
(strip). A switch device is mounted on the inside of the strip and is actuated by an actuator arranged in a substantially parallel relationship with the outer strip. The actuator moves in response to bending of the upper and lower strips together. The switch is located below the mattress on which the patient lies. However, this device must be reset each time the patient leaves the bed and returns to the bed. Also, this device cannot be used when placed on a hard surface. Since most hospital beds use a rigid frame on which the mattress is placed, this device cannot be used in most hospitals.

In another arrangement disclosed in US Pat. No. 4,263,586, an electrical switch and an alarm device are provided which are actuated by pressure and have a spring, the switch being located at the foot base of a hospital bed and the bed being moved by the patient. When occupied, the weight causes the switch to open, but when the patient leaves the bed, the switch closes by spring action and an alarm is activated.

[0007] These various sensing and monitoring devices are concerned with activating alarms for hazardous conditions.

[0008] The various methods proposed have focused on the problems that arise with patients occupying a bed.
This problem is relevant when a patient tries to leave the bed, who is extremely frail and unable to support himself with his legs and suffers considerable pain when falling to the floor. However, these methods are complex and costly.

[0009]

SUMMARY OF THE INVENTION It is an object of the present invention to eliminate the disadvantages of the prior art monitoring devices.

[0010]

According to the present invention, there is provided a sensor device used to be supported by a support frame for monitoring an occupant of a bed, comprising:
A substantially flat lower member; a substantially flat upper member that can flex downwardly by the weight of the occupant and is substantially parallel to the lower member with a slight spacing member; An attached upper member; sensor means disposed between the upper member and the lower member, wherein the weight of the occupant causes the upper member to flex downwardly resulting in pressure and the presence of the occupant on the bed. A sensor means for generating a signal indicating that the upper member is at least one point sensor responsive to the downward deflection of the upper member, wherein the upper member is rigid, and The sensor is characterized in that it is arranged so as to be deflected downward by weight and to apply pressure to the sensor even when the weight of the occupant is applied to the upper member at a position different from the position of the sensor. Sensor device is provided.

[0011] In an extension of the basic concept of the invention, the device also comprises means for indicating the movement of the patient on the bed.

This arrangement provides a sensor device that uses a simple and effective point sensor and can monitor the pressure experienced over a wide area of the bed.

Preferably, the device is used between a bed mattress and a support frame. Preferably the lower member is rigid so that it can be placed on various support frames without affecting the operation of the device.
For example, the support frame is a plate or a mesh metal grid.

The upper and / or lower member is preferably a metal plate and has a thickness of 1 mm to 5 mm.
And preferably 2 mm.

The distance between the upper and lower members is 5 cm
Below, more preferably about 1 cm, whereby a compact and fragile sensor unit is obtained.

Preferably, the width of said member is at least 20
cm.

Preferably, the sensor is mounted at the center of the sensor device.

The upper plate and the lower plate are preferably spaced apart by hard mounting means disposed at opposite ends of the sensor unit, and the sensor is located at the center of the opposite ends. The mounting means is preferably two parallel spacing members, the plates being substantially unsupported between the spacers.

When occupying the bed (when the bed is occupied by the patient), the weight of the occupant causes the upper member to flex downward. When the occupant leaves the bed, the upper member flexes upward and its movement is detected by a sensor located between the plates.

Preferably, the sensor unit is connected to an alarm indicator, which is activated when the occupant leaves the bed on which the sensor unit is mounted. The alarm may be an audible alarm, which alerts a nearby nurse or other caregiver. Also, the unit may be connected to a nurse call system provided at the hospital, so that the number of occupied beds can be monitored by one nurse at the nurse call control desk.

Preferably, the sensor unit is connected to a control unit responsive to the sensor unit having a light alarm such as a flashing light emitting diode. The control unit is mounted on the bed in a visible position. This is so that when the occupant leaves or falls off the bed, it can be easily confirmed.

[0022] The mere movement of the occupant, such as moving from one side of the bed to the other, does not activate the alarm indicator for a long time, but the sensor unit is activated when the patient approaches the edge of the bed and is at risk of falling It may be used to indicate that.

The sensor may be a micro switch. However, it is preferably of the type having two interacting parts, one part being attached to one member (plate). For example, the sensor may consist of a reed switch attached to one member and a magnet attached to the other member. The sensor may include a Hall effect semiconductor device attached to one member and a magnet attached to the other member. These sensors may be very small, for example less than 1 cm in height, and thus the invention is ideal for use when properly positioned.

In a particularly useful embodiment, the sensor may be a linear output Hall effect transducer that can be used to monitor low occupant movements, such as agitation, rollover, rotation, and the like. In such an embodiment, if the transducer measures an excessive loss of weight on the sensor, it will activate any of the alarms already described in connection with the switching device.

By arranging two switch devices on both sides of the sensor unit, it is possible to monitor a restless state. That is, turning or turning of the patient from one side to the other activates both switches alternately and continuously, which can be monitored using the associated electrical circuit.

According to the invention, there is further provided a bed including a bed frame and a support sheet, wherein the support sheet flexes to a predetermined extent when the bed is occupied by the patient, regardless of the position of the patient on the bed. In such a bed, there is at least one point sensor, which is simply an on-off limit switch or a weight-responsive transducer, which is arranged between the bed frame and the support sheet to reduce the deflection. A bed is provided which detects and activates the sensor means.

The sensor means may be arranged on the bed at the time of manufacture of the bed, or may be separately attached to a part attached to the bed frame. Next, the present invention will be described in more detail with reference to the accompanying drawings.

[0028]

DETAILED DESCRIPTION OF THE INVENTION With reference to FIG. 1, an improved sensor unit 2 comprises upper and lower thin but hard steel plates 4, 6 each of which is approximately two.
It is rectangular with a thickness of mm and has sides 12, 14 of approximately 30 cm × 60 cm. The plates are spaced approximately 10 mm apart from each other by metal bars (spacers) 8,10 having a square cross section. Spacers 8 and 10 are
The plates 4 and 6 are located parallel to each other around the short sides. When the sides of the plate are unsupported and the substantially rigid upper plate 4 flexes, the upper plate becomes shallow U-shaped over its entire width.

A point (contact) sensor 16 is located between the plates, in a central position between the spacers 8, 10 and preferably in a geometrical central position between the two.
Can detect the vertical movement of the plate 4 or the center of the steel sheet. A signal from the sensor 16 is sent to a control unit (shown in FIG. 2) via a sensor cable 18.

As seen in FIG. 2, the sensor unit 2 is located above the bed base 20, below the mattress 22, and assuming that the patient is located at least entirely in the center of the mattress, its buttocks. Bed head 2 under position
4 is arranged near. When the patient is lying on the mattress at that position, the upper plate 4 of the sensor unit
Deflects downward, and its movement is detected by the sensor 16. The sensor is appropriately set to detect the degree of movement of the upper plate 4 caused by the weight of the person, and preferably also detects a person with a small or light weight of at least 50 to 60 kg. Because the sides of the sensor are unsupported and the upper plate 4 is rigid, movement of the patient moving to one side of the bed causes a lower deflection of the upper plate 4 which is detected at the position of the sensor 16. Is done. If the patient then approaches dangerously near the side of the mattress, or actually leaves the mattress, the upward return movement of the upper plate 4 is automatically detected and a signal is sent via the sensor cable 18. It is sent to the control unit 26.

The control unit 26 includes an audible alarm, a flashing light emitting diode 30 of light (not shown), and may be provided with a conductor 28, which connects the control unit to a hospital or nursing home nurse. Connect to the patient port of the station. Control unit 26
May be linked to a portable receiver carried by the care staff wirelessly. These receivers alert the care staff that the bed is no longer occupied and alert the location information about the bed.

The sensor unit 2 includes upper and lower housing sheets 4 and 6 for protecting and functioning the sensor 16.
It can be understood that the sensor unit 2 has a durability. The unit 2 is a self-attaching type in that the unit 2 only needs to be placed between the hard bed base 20 and the mattress 22. The sensor unit 2 may be used with the alarm device described in connection with the embodiment of FIGS.

The sensor may be a micro switch. However, the sensor preferably has two interactive parts, so that each part is attached to a respective plate. For example, the sensor may be composed of a reed switch arranged on one member and a magnet arranged on the other member. Further, the sensor may include a Hall effect semiconductor device disposed on one member and a magnet disposed on the other member.
These sensors may be very small, for example less than 1 cm in height, and thus the invention is ideal for use when properly positioned.

It is also preferred to use a large sensor that does not fit in the 1 cm spacing range between plates 4 and 6. In this case, the microswitch is attached to the base of the lower plate 6 so that a part thereof protrudes from the hole of the lower plate 6 and comes into contact with the upper plate 4. This configuration is particularly useful when the bed base 20 is a metal mesh finish supported on a frame. The exposed portion of the sensor is placed after the sensor unit is placed on the bed base and then during mesh finishing.

The sensor 16 may be of a linear response type, for example, a linear output Hall effect transducer (linea) which can be used to monitor low-level movement of a bed occupant.
r output Hall Effect transducer). The patient's restlessness could be recorded on a recording device to determine medical needs or to check later for other care.
If the patient leaves the bed, the same device may trigger an alarm via the control unit 26.

The control unit 26 can also be connected to a moisture detector which monitors the bed sheets of patients who cannot control bowel movement. The alarm device oscillates when moisture is detected, allowing the nurse to take action to improve the patient's overall comfort level and prevent bedsores.

Returning to a further aspect of the invention, FIG.
Standard hospital bed 11 including frame 112 on 14
Indicates 0.

The frame 112 has one or more horizontal bars 116 extending between its long sides and is usually covered with a rectangular metal sheet 118 which is the same as the frame.
It has light ribs indicated by 0 to increase its strength.

The sheet 118 is usually pop riveted to a frame 112 formed of a rod having a hollow rectangular cross section. When a patient lays on such a bed, it sags and buckles. This bed deflection or strain can be used as a very simple and effective means of monitoring patient pressure and movement in the bed. As an example of this aspect of the invention, I suggest removing the sheet 118 and mounting a sheet 122 of an appropriate thickness of rubber or other compressible material on the frame 112 before the sheet 118 is replaced. I do.

Further, a micro switch sensor 124 having an operation button 126 is disposed at the center position of the horizontal bar 116 shown in FIG. The sensors are typically located near the buttocks when the bed is occupied, and the microswitch sensors are located in holes 126 in seat 122. The bed may have a connection control box 127, which is removably mounted on the bottom of the bed frame, out of reach of the patient. Box 127
May include an on / off shut-off switch, a battery to provide power, a light to warn that the battery is dead, and an audible alarm to respond locally to bed occupant movement. The box is electrically connected to the microswitch to shut off the switch and may include an on / off warning light.

The configuration of FIG. 4 shows a state where the bed is not occupied, but when occupied, the sheet 118 bends as described above, and as shown in FIG.
As a result, the bent sheet 118 is moved in the opposite direction by pressing the button 126 of the microswitch. This state is actually a monitoring state, but the microswitch is in the position of FIG. 5 and the switch is closed, and the alarm or monitoring circuit is shut off. However, when the switch is open, as shown in FIG. 4, an alarm or monitoring circuit will connect and signal to a remote location where the person monitoring the bed occupant will be.

Thus, under normal conditions where the bed is occupied by a person, the microswitch 124 is under circuit break conditions. However, when the person leaves the bed, the sheet 118 returns to the state of FIG. 4 due to its own elasticity and the re-expansion of the rubber layer 122. The alarm is activated and the person monitoring the patient can immediately know that the patient has left the bed. If such a patient is weak enough to be unable to walk, the monitoring person needs to know immediately when the patient leaves the bed.

It will be understood that the bed shown in FIG. 3 shows the basic structure of the bed, and of course uses a mattress, a cover sheet and the like.

FIGS. 6, 7 and 8 show an application or another embodiment of the present invention.

FIG. 6 shows a configuration in which the microswitch 124 is fixed to the U-shaped bracket 130 by a pair of screws 132, 134. Bracket 130 is horizontal bar 11
6, and is fixed to the horizontal bar by a clamp screw 136. Clamp screw 136 extends through the leg of bracket 130 and frictionally engages the wall of cross bar 116 as shown.

The microswitch 124 is shown in FIGS.
It should be understood that the position is set so as to perform the same function as described for. In this example, the compressible material is a strip 138 that only covers the top of the crossbar 116, and need not be a complete sheet of compressed material as in the examples of FIGS.

With this configuration, the microswitch 124
Can be attached to and removed from the bar 116 very easily. Similarly, it is easy to adjust the vertical position of the microswitch with respect to the horizontal bar 116, so that the microswitch can be operated most efficiently. FIG. 6 also shows a sheet-like metal plate 116 and a plunger 126. Mattress 138A
Is located on the plate 118.

In the configuration described so far, only a single microswitch 124 is provided. However, in the configuration of FIG. 7 showing an end cross section of a related member of the bed, the center line of the bed is denoted by reference numeral 140. And a horizontal bar 116 is shown.

The two micro switches 124A, 124
B is symmetrically located on opposite sides of the centerline 140, and a bracket 130 of sufficient length extends along the crossbar 116 to support the microswitches 124A, 124B. The bracket 130 is secured to the crossbar 116 in a manner similar to FIG. 6 except that two or more clamp screws are used. The control box 127 shown in FIG. 3 is preferably used in any of the embodiments, and in this case also should be fixed to the end rail of the bed frame in the same configuration as shown in FIG.

The advantage of the arrangement of FIG. 7 is that because two microswitches are used to operate according to the deflection of the seat 118, the microswitches not only indicate that the patient has left the bed, but also that the It is stable and can also indicate that it moves from one side to the other, in which case the microswitch on each side changes its state,
One is “on” and the other is “off”. In such a configuration, a light can be used to know the state at a position away from the bed. The light may be, for example, a green light, in which case the caregiver of the patient may know if a particular patient is moving on the bed or is unstable and needs attention.

When both switches are open, that is, when the seat 118 is flexed upward, the caregiver knows that the patient on one seat is away from the bed and must take appropriate action. .

A configuration similar to the switch sensor located in both the sensor units of FIGS. 1 and 2 may be used here to achieve a similar effect.

In FIG. 7, micro switches 124A,
The spacing of 124B is approximately 12 inches, but it is clear that the most appropriate spacing can be chosen. It is preferable that both the micro switches 124A and 124B are adjustable so that the distance between them can be adjusted in the length direction of the bracket 130.

Again, the horizontal bar 116 and the bed support sheet 1
18, a suitable compressible strip 138 is provided.

In any of the previously described embodiments, deflection of the sensor structure is detected. However, when the patient is in bed, the entire bed structure is distorted. Thus, in another embodiment of the invention, no microswitch is used, instead a strain gauge 144 is mounted below the sheet 118, and the strain gauge is stressed by the stress of the bed structure. Alternatively, instead of the compression strip 146, an electronic load cell that detects a change in weight occurring in the plate 118 immediately above may be used. The stress or weight change shown on the load cell or strain gauge may be used to activate the previously described indicating means.

Obviously, when a strain gauge or load cell is used, it should be located at the most appropriate location in the bed structure.

It should further be understood that the various types of sensors described above can be used interchangeably. Although one type of sensor is described, any sensor with equivalent function can be located at the same location or other suitable location. However, it is pointed out that a general characteristic of the sensor used is that it is a point sensor capable of detecting a change in the interval or weight of a small portion where the patient's weight is applied.

[0058]

The present invention provides a cost-saving, durable and reliable means for monitoring occupants of a bed or the like.

It should be understood that various modifications and applications may be made by those skilled in the art without departing from the scope of the present invention.

[Brief description of the drawings]

FIG. 1 is a perspective view of a sensor unit according to an embodiment of the present invention.

FIG. 2 is a side view when the sensor unit of FIG. 1 is used for a bed.

FIG. 3 is an exploded perspective view of a bed according to a further aspect of the present invention.

FIG. 4 is a partially enlarged cross-sectional view showing an arrangement of micro switches in the configuration of FIG.

FIG. 5 is a view similar to FIG. 4, but showing a partially enlarged sectional view showing a state in which the microswitch is closed;

FIG. 6 is a longitudinal sectional side view showing another detailed aspect of mounting the microswitch.

FIG. 7 is a longitudinal side view of a further aspect of the present invention.

FIG. 8 is a view similar to FIG. 6, but illustrating the use of a strain gauge.

[Explanation of symbols]

2 Sensor unit 4 Upper member (upper steel plate) 6 Lower member (lower steel plate) 8,10 Spacer 16 point sensor 22 Mattress 26 Control unit 30 Alarm 110 Hospital bed 112 Bed frame 116 Horizontal bar 118 Flexible sheet 122 Rubber sheet 124 Microswitch

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H01H 35/00 H01H 35/00 Q

Claims (13)

[Claims] 1. A sensor device used to be supported by a support frame for monitoring an occupant of a bed, comprising: a substantially flat lower member (6, 116); An upper member (4,118), which can flex downwards due to the weight of the occupant, and which is mounted substantially parallel with a small spacer to said lower member (6,116). A sensor means (16, 124, 144) disposed between the upper member (4, 118) and the lower member (6, 116), wherein the weight of the occupant causes the upper member to deflect downward; ,
Sensor means for receiving pressure and generating a signal indicative of the presence of an occupant on the bed; said sensor means (16, 124, 144) responsive to a downward deflection of the upper member (4, 118). At least one point sensor, wherein the upper member (4,118) is rigid and deflects downward due to the weight of the occupant of the bed so that the occupant's weight is different from the position of the sensor. Even in such a case, the sensor device is arranged to apply pressure to the sensor. 2. The sensor device according to claim 1, wherein the lower member (6, 116) is substantially rigid. 3. The sensor device according to claim 1, wherein the upper member and / or the lower member are metal plates (4, 6, 116, 118). 4. The sensor device according to claim 3, wherein the thickness of the plate is 1 mm to 5 mm. 5. The sensor device according to claim 1, wherein the distance between the upper member and the lower member (4, 6) is 5 cm or less. 6. The sensor device according to claim 1, wherein the width of the upper member and the lower member is at least 20 cm. 7. The sensor means (16, 124, 14)
7. The sensor device according to claim 1, wherein 4, is mounted at the center of the sensor device. 8. Two parallel spacers (8, 10) are provided between the upper member and the lower member (4, 6),
8. The sensor device according to claim 1, wherein the upper member (4) is not substantially supported between the spacing members. 9. The sensor according to claim 1, wherein the sensor means is at least one electrical transducer of the type having two interacting parts, said parts being attached to each member (4, 6). The sensor device according to 3, 4, 5, 6, 7, or 8. 10. The sensor means (4, 11)
8, 6, 116) wherein at least one converter produces a continuously varying output in response to an interval of
The sensor device according to 2, 3, 4, 5, 6, 7, 8, or 9. 11. An alarm signal generator configured to generate a perceptible alarm signal when the weight of a bed occupant is lost.
The sensor device according to 4, 5, 6, 7, 8, 9 or 10. 12. A bed comprising a bed frame (110) and a support sheet (118), wherein the support sheet comprises:
At least one point sensor (124, 1) in a bed that bends to a predetermined degree when the bed is occupied by the occupant, regardless of its position on the bed.
44), wherein the point sensor is simply an on-off limit switch or a weight-responsive transducer, and is disposed between the bed frame (110) and the support sheet (118), and detects the deflection to detect the deflection. Bed for operating the means. 13. The bed according to claim 12, wherein the point sensors (124, 144) are arranged at the center of both ends of the bed.