WO2021105139A1

WO2021105139A1 - Apparatus for detecting a person in a bed

Info

Publication number: WO2021105139A1
Application number: PCT/EP2020/083243
Authority: WO
Inventors: Armin Hille
Original assignee: Dewertokin Gmbh
Priority date: 2019-11-25
Filing date: 2020-11-24
Publication date: 2021-06-03

Abstract

The invention relates to a method for detecting a person in a piece of reclining furniture, wherein the piece of reclining furniture has a number of sensors (10) which are arranged spaced apart from each other on the piece of reclining furniture, and at least one evaluating device to which the sensors are coupled. The method is characterized by the following steps: - providing position information for each of the sensors (10); - measuring a force acting on each sensor (10); - transmitting a value which corresponds to the force from each of the sensors (10) to the evaluating device; and - determining and outputting a piece of position information regarding a person lying in the piece of reclining furniture on the basis of the transmitted values of the force while taking into account the piece of position information. The invention furthermore relates to an apparatus for detecting a person in a piece of reclining furniture, having a number of sensors (10).

Description

Device for detecting a person in a bed

The invention relates to a method and a device for detecting a person in a piece of furniture. The reclining furniture has a number of sensors that are spaced apart from one another, the sensors being set up to measure a force that is exerted on the respective sensor by a person in the reclining furniture, and one of the force output the corresponding value. There is also at least one evaluation device to which the sensors are coupled and which is set up to record and evaluate the values output by the sensors.

Methods and devices for detecting a person in a piece of furniture are known in the prior art. You can for example be inte grated in mattresses and detect the presence of a person in the furniture. Other devices also allow a movement of the person in the furniture to be detected and this feature to be passed on to an ad.

These prior art devices can be used to support people with an existing pressure ulcer or to prevent pressure ulcers. However, these devices and methods do not offer reliable support to the effect that these devices and methods can monitor preventive measures in and of themselves.

The invention is therefore based on the object of providing a method and a device of the type mentioned at the outset that reliably and effectively monitors treatment and preventive measures against pressure ulcers and thereby supports them.

A method according to the invention is characterized by the following steps: Position information is provided for each of the sensors. Then a force acting on each sensor is measured and a value corresponding to the force is transmitted from each of the sensors to the evaluation device Person determined and issued. In a device according to the invention, the at least one evaluation device is set up accordingly to determine position information on the person in the furniture on the basis of the values of the sensors, taking into account their arrangement on the furniture. By assigning measured force values to (previously known) position information from the sensors that are arranged on the furniture, in accordance with the invention not only the presence of a person in the furniture can be detected and a movement profile can be created, but specific location information about the person can be derived . The position information includes, for example, in which of the following positions or postures the person is in the piece of furniture: in a side position, a back or prone position, a sitting position or in another position.

On the basis of the way in which the resting person is positioned or the position of the person changes, conclusions can be drawn about treatments, patterns or preventions and these can be displayed. It can be monitored that the person is not in a certain position for too long. Nursing staff or relatives can be asked by a warning signal to relocate the person accordingly. The permanent position detection possible by the method according to the invention can also be saved for documentation purposes.

Possible embodiments of the invention are described below. The embodiments mentioned can be carried out individually as well as combinable with one another.

The reclining furniture can be a bed. An armchair can also be seen as reclining furniture, provided it has an adjustment option for a support device such as a head and / or foot section. As a support device, spring cores, Lat tenroste or bed frames together with a flat receptacle come into question, wherein a mattress or other padding is usually arranged on the support device.

In an advantageous embodiment, the sensors each have a bending force sensor with a strain gauge. As an alternative or in addition, piezo force sensors can also be used. The sensors are each designed so that they can differentiate between more than two different values for the force. The sensors are preferably designed to be able to measure and output a large number of force states. The output can take place as a continuous analog value (in the form of a signal) or as a discrete digital value. A sensor that only can distinguish between two states, e.g. B. loaded and not loaded is not suitable as a sensor in the context of the present application.

The sensors can, for example, be attached to the support device below a mattress or padding. In alternative configurations, they can also be completely or partially embedded in the support device, but in each case in such a way that they are able to at least partially detect a force acting on the support device via the mattress or upholstery.

In a further advantageous embodiment, absolute values of the force values are used to determine the position information. Alternatively or additionally, a difference in the values of two sensors, in particular neighboring sensors, can be used to determine the position information. The difference can be normalized via the distance between the two sensors considered.

The values of the sensors are particularly advantageously processed as a 2-dimensional image with the aid of the position information and evaluated with the aid of image recognition processes. Well-known and established methods of image processing, e.g. edge recognition, contour recognition or pattern recognition, can be used. The process can use self-learning techniques, e.g. in connection with neural networks.

The change in this image over time is a measure of the ability to move and the mobility of the person at rest. Furthermore, the time sequence and the duration of this image can also have a specific scheme, which the evaluation unit can also recognize. For this purpose, at least one pattern previously stored in the evaluation unit can be compared with the pattern currently generated by the person and it can be determined which position has been taken and whether the person is moving or moving inside the piece of furniture, whether the person is moving with outside help or whether the person leaves the furniture, whether the person receives therapy, and / or whether the person receives body care by caregivers.

In one embodiment, all images and / or the positional information and / or movement sequences determined therefrom can be recorded and stored. The data and events are stored in a non-volatile memory, although the data can be individually erased.

At least some of the data and events can be evaluated in such a way that they can be used as documentation for the care that has taken place for the respective person to be cared for. Such data can be evaluated directly or further and fulfill the goal of having made an entry in the personal file of the person to be cared for. In this way, there is a high level of support for the nursing staff when the device completely independently undertakes the daily documentation for the respective caregiver or at least prepares it in such a way that the caregivers only have to confirm this documentation for importing into the electronic patient record . As a result of this simplification of work, the nursing staff has more time to devote more time to their actual concerns, the service to people.

The evaluation device advantageously comprises at least one microprocessor and at least one executable program for operation by the microprocessor.

The evaluation device can comprise signal or data inputs which are coupled to the sensors. Signal transmission from sensor to sensor is also possible, so that a group (chain) of sensors is only connected to one input.

The program is able to record and process the input-side signals in such a way that an image of the input-side signals can be created, evaluated and, if necessary, visually displayed on a display. Thus, an image of the person acting on the support device can be detected, recorded and reproduced with regard to their entirety or with regard to individual body regions. The location and position of the person in the furniture can thus be recorded. The force intensity which acts on the respective body region can also be recorded. The program can preferably record changes in the respective position and / or changes in the respective force intensity. The program is also preferably able to send information to the caregiver if the person to be cared for has not changed their position for a long time or for an adjustable and predetermined time.

In addition, the program can be able to save, document and / or export events. Events can be: changes in the position of the person in the furniture, changes in the intensity of force on the respective Body region, changes both in position and in force intensity as a measure of a transfer or a care measure by the caregiver.

The program is able to generate a characteristic value, for example in the form of a numerical value, corresponding to the events and / or to the frequency of the events, as well as to document and / or export it. An export takes place in data form and can also be visualized on paper or on a display by a downstream device. The export can be done wirelessly or wired or by means of a movable memory such as a USB stick.

The sensors are preferably arranged on or in the support device in the form of a grid, e.g. a regular rectangular grid. More generally, the arrangement can take place in the form of a matrix, in which a plurality of sensors are distributed on the support device, so that an image of the person using the reclining furniture can be made. The surface density in which the sensors are arranged can be constant via the support device. However, it is also conceivable that areas of the support device which are particularly meaningful for determining the position are more densely covered with sensors than other areas. Such relevant areas are e.g. the area in which a pelvis or back of the person is usually positioned.

The matrix or the grid of the sensors extends in principle in one plane. However, this plane can be curved or wavy.

Another arrangement provides for groups of sensors, which can optionally also be coupled to separately assigned evaluation units. A group preferably includes sensors that are spatially adjacent to one another. A first matrix is e.g. in the area of the shoulders, a further matrix in the area of the coccyx and pelvis and a further matrix is provided in the area of the legs of a person at rest. The area of the legs can be divided into further sub-groups, e.g. into one area of the knees and another area of the feet.

The invention is explained in more detail below on the basis of exemplary embodiments with the aid of figures. The figures show:

1 shows an embodiment of a piece of furniture with a sensor matrix in a symmetrical representation; FIG. 2 shows an isometric illustration of a sensor of the sensor matrix according to FIG. 1; FIG.

3 shows a sectional illustration of the sensor according to FIG. 2; and

4, 5 each show an isometric exploded view of the sensor of FIGS. 2 and 3 from different viewing directions.

Figure 1 shows a bed as an example of a piece of furniture in an isometric view. The bed has a frame 1 which is raised on feet 2 in the example shown. The frame 2 carries a support device 3, which in the present case comprises different, partially articulated support plates. The support device 3 is used to support a padding element, such as a mattress.

In the illustrated embodiment, the support device 3 is subdivided into a middle part 4 fixed relative to the frame 1 and a back part 5 that can be pivoted relative to this middle part 4. There is also a two-part leg part 6 that can be bent along the connecting lines of the two parts and thus erected in a roof-like manner. It is noted that the division of the support device 3 into the various parts 4-6, some of which can be moved relative to one another, is purely by way of example. The sensor arrangement explained below can also be implemented with one-piece, continuous support devices 3 or with support devices 3 that are subdivided differently than shown.

If a support device 3 has parts 4 - 6 which can be moved relative to one another as shown, these are preferably movable via an electromotive adjustment device. Such a device is not visible in the present case, but can be arranged in a known manner in the area of the frame 1 below the support device 3. It can comprise one or more adjustment drives that make the dargestell te movement of the parts 5 and 6 by an electric motor. The adjustment drives are generally connected to one or more control devices, which in turn are controlled via one or more wireless and / or wired-coupled operating units.

According to the application, a matrix of a plurality of sensors 10 is provided in the bed shown, which are designed as force sensors and which are each able to apply a force transmitted to the support device 3 measure and output in the form of an analog and / or digital electrical signal. In the exemplary embodiment shown, 45 sensors 10 are provided purely by way of example, which are arranged in nine rows of five columns each in the form of a rectangular and regular grid. The illustrated arrangement and number of sensors 10 is purely exemplary. In the context of the application, sensors 10 can also be posi tioned in other geometric arrangements and, in particular, be provided in different areas of the bed in different densities.

In the example shown, the sensors 10 are mounted on the plate-shaped support device 3. The mattress provided as padding rests partly on the support surface 3 and partly on the sensors 10. At least when the mattress is loaded by a user, but as a rule already by the weight of the mattress itself, the sensors 10 will be pressed into the mattress. They are preferably made so thin that they are not perceived as annoying by a person using the bed. In alternative configurations, the sensors 10 can also be completely or partially embedded in the support device 3, but in each case in such a way that they are able to at least partially detect a force acting on the support device 3.

The sensors 10 are designed to be able to measure and output a large number or a plurality of Kraftzu states. The output can be in the form of a continuous, analog signal or as a discrete digital value. A sensor that can only differentiate between two states, e.g. B. loaded and not loaded is not suitable as a sensor in the context of the present application.

In FIGS. 2-5, an embodiment of a suitable sensor 10, e.g. B. for use in the bed shown in FIG. Figure 2 shows the sensor 10 in the assembled state in an isometric oblique view. FIG. 3 shows a section through the sensor 10. FIGS. 4 and 5 are isometric exploded views from different viewing directions. FIG. 4 shows the sensor in the viewing direction of FIG. 2, whereas FIG. 5 shows a view of the underside of sensor 10.

The sensor 10 has a base 11 which is provided with fastening holes for screwing the sensor onto the support device 3 according to FIG. 1, for example. On the base 11, a cover 17 is placed, which has a substantially perpendicular edge 171 protruding from the base 11 and an in the Has hood 172 extending substantially parallel to the base 11. The hood 172 is designed to be corrugated so that it can be pressed in in its central area opposite the rigid edge 171. The middle area of the hood 172 represents a support area 173 which, as can be seen in FIGS. 3-5, transmits a force acting on the hood 172 inwards into the sensor 10.

The cover 17 is fastened to the base 11 in that the base 11 has an edge 113 on a base plate 111, over which the cover 17 is slipped, the edge 171 of the cover 17 being held either by frictional engagement and / or by latching.

Within the edge 113, a sensor support surface 112 is formed on the base plate 111. A bending force sensor 12, which comprises a bending arrangement 121, rests on this support surface 112. This is gebil det in the example shown by an approximately square sheet metal element with punched holes. Two tongues 122, starting from an outer frame, are separated by the punchings. These tongues 122 are connected to one another at the top via a riveted bridge 123. A strain measuring sensor 124 is clamped or glued between the bending arrangement 121 and the bridge 123 and is contacted via a connecting cable 125. On the upper side of the bridge 123 an expression is attached, which forms a force introduction point for the force-bending sensor 12. At this point applied force leads to a bending of the web between the tongues 122 ge compared to the outer edge of the bending arrangement 121, which is detected by the strain measuring sensor 124.

Above the bending force sensor 12 (viewed from the base 11) there is a presently round intermediate disk 14, for example a metal disk which is not or only very slightly bendable. It is held in position laterally by a guide frame 13 made of thinner sheet metal or plastic. The intermediate disk 14 rests (apart from the easily deformable guide frame 13) only on the force application point on the bridge 123 of the bending force sensor 12. Force acting on the intermediate disk 14 from above is thus bundled and transmitted to the force introduction point of the bending force sensor 12 provided for this purpose.

A piezo force sensor 15 is arranged on the intermediate disk 14, which preferably rests on the intermediate disk 14 over its entire surface. Here are those Intermediate disk 14 and the piezo force sensor 15 are round and have the same diameter. The piezo force sensor 15 is provided in a known manner with a larger, disk-shaped electrode and a piezo material applied to this in a central area, on the top of which a second electrode is arranged. The two electrodes can be contacted via a connection cable 151. The piezo force sensor 15 made it possible to determine a force applied to the central electrode.

A further intermediate disk 16, which is preferably made of a softer material, is placed on this middle electrode, so that it does not damage the electrode of the piezo force sensor 15. The further intermediate disk 16 is nevertheless stable enough not to be damaged by forces acting on it. You can for example consist of a hard rubber material. The support area 173 of the hood-shaped cover 17 rests on this further intermediate disk 16.

Thus, a force acting from above is transmitted to the cover 17 via the support area 173 via the piezo force sensor 15 to the bending force sensor 12. The same force is applied to both sensors, the piezo force sensor 15 and the bending force sensor 12, at least when this force acts statically on the cover 17. In this context, static means that the force changes at most in the hertz or sub-hertz range.

In the construction shown, the force measuring range for the bending force sensor 12 can be larger than the force measuring range of the piezo force sensor. Even if the bending force sensor 12 and the piezo force sensor 15 in the sensor 10 are subjected to the same static force, a force measurement for the static case by the bending force sensor 12 is then preferred. For forces that change with higher frequencies, e.g. In contrast, changes in force due to structure-borne noise picked up by sensor 10 can be detected better by faster-reacting piezo force sensor 15 than by bending force sensor 12.

In applications in which, in particular, a static force is detected, the sensor arrangement 10 can also be constructed without the piezo force sensor 15. In this sense, this represents an additional option in order to also record higher frequencies, in particular structure-borne noise. Furthermore, the piezo Force sensor 15 suitable to be able to detect rapid movements such as trembling of the user of the furniture.

The connection cables 125 of the bending force sensor 12 or 151 of the piezo force sensor 15 indicated in FIGS. 4 and 5 can be combined in a connection cable of the sensor 10 and led to the outside through the cable outlet 114.

The sensors 10 are connected to an evaluation device, not shown in the figures, which reads in the values of the measured force provided by the sensors 10. The evaluation device knows the positions of the individual sensors 10 on the support device - they can, for example, be stored in a non-volatile memory of the evaluation device when the evaluation device is set up.

The evaluation device can be connected to all sensors 10 in a star shape. Alternatively, however, the sensors 10 can be designed in such a way that they enable signals or data to be forwarded from sensors 10 connected to them. In this case, chains of sensors 10 can be formed, the entire chain only making contact with one connection of the evaluation device.

The sensors 10 can be grouped, for example in such a way that all sensors 10 which are arranged on one of the parts 4-6 of the support device 3 form a group. Each group can form a chain. However, it is also conceivable that all sensors 10 are physically arranged in a chain, but are logically assigned to different groups.

When the bed is used by a person, the values of the sensors 10, possibly separately for groups formed, are processed as a 2-dimensional image with the aid of the position information and can be evaluated, for example, with the aid of image recognition methods. Known and established image processing methods, such as edge recognition, contour recognition or pattern recognition, can be used. The method can use self-learning techniques, for example in connection with neural networks. A position of the person can then be determined and displayed or output by the evaluation device, for example via a network to a data processing device of a care facility or a mobile device of the care staff. Different positions of the person in the bed are distinguished by characteristic force patterns which the arrangement of the sensors 10 experiences. The prone position or position on the back show, for example, a force pattern extending essentially along the longitudinal axis of the bed. In the case of side contact, the force pattern is narrower and possibly curved so that a distinction is possible. If the person is sitting in bed, the force pattern is concentrated more centrally in the area of the buttocks, possibly with separate local force points due to support by the arms. As a side effect, it can of course also be determined whether the person is in bed at all.

The position taken can be recognized on the basis of such fundamental characteristics or on the basis of a pattern comparison. For this purpose, at least one pattern previously stored in the evaluation unit is compared with the pattern currently generated by the person. In this case, the evaluation device can also be designed to be self-learning, e.g. with the help of a new ronal network or comparable methods of AI (artificial intelligence).

The temporal change in this image or the position determined from it is a measure of the ability to move and the mobility of the person at rest. Furthermore, the time sequence and the duration of this image can also have a specific scheme, which the evaluation unit can also recognize.

The captured images and the location information determined from them can be used as documentation for the care that has taken place for the respective person to be cared for. Such data can be evaluated directly or further and it fulfills the goal of having made an entry in the personal file of the person to be cared for. In this way, there is a high level of support for the nursing staff when the device completely independently undertakes the daily documentation for the respective caregiver or at least prepares it in such a way that the caregivers only have to confirm this documentation for importing into the electronic patient record. As a result of this simplification of work, the nursing staff has more time to devote more time to their actual concerns, the service to people.

The control device is designed to provide the data and information generated for documentation of the care that has taken place and in the personal file of the person to be cared for. The transmission of this data and information takes place via a suitable interface of the control Facility. In a first embodiment, the interface has a wired data output for connection to a wired data network of the hospital or the care facility. For the sake of simplicity, the wired network can be formed according to a standardized type such as LAN, USB or can even be designed as a standardized telephone network. A further version of the interface provides for a wireless transmission link in the manner of a WLAN or DECT or Bluetooth standard. Alternatively, a proprietary wireless transmission path can be used. Even with wireless transmission, the data can be transmitted directly to the electronic and personal file of the person to be cared for, or collected and temporarily stored in an area of a section of a hospital or a care facility.

Furthermore, the aforementioned data processing device of a nursing facility or a hospital, the aforementioned mobile device of the nursing staff, can be designed in such a way that all data and information generated by the sensors 10 are queried or displayed by the mobile device. One embodiment also provides that the data provided by the respective control device to the network are promptly transmitted to the mobile device and are displayed. A mobile device can be designed as a telephone, smartphone or tablet computer. A real-time display would be conceivable to display mobility or absence information to the nursing staff. In this way, the nursing staff can quickly and promptly recognize whether, for example, a person to be cared for has moved out of bed, so that their own work organization can be optimized. The program, or the program of the mobile device, can be set so that when the absence of the person to be cared for is detected from the bed, an optical and / or acoustic alarm or silent information is output to the care staff. The same can also be done with a position detection. If, for example, the person to be cared for is to be kept on their side for a while, because a pressure ulcer is to be prevented on the back, or if a pressure ulcer is already present, the same alarm or the same information can be transmitted to the mobile device and the nursing staff can quickly and intervene promptly to help the person to be cared for back into the pressure ulcer relief or pressure ulcer preventive position.

Furthermore, the data network can also be the mobile radio network, at least in sections. This makes it possible to cover greater distances between the Bridge control device and the mobile device. It is also possible to transmit or mirror all data and information or a selection thereof to a mobile device of the relatives of the person to be cared for, if they want to be informed about the condition of the person to be cared for.

Reference number

1 frame

2 feet

3 support device

4 middle section

5 back section

6 leg section

10 sensor

11 base

111 base plate

112 sensor surface

113 margin

114 cable outlet

12 Bending force sensor

121 bending arrangement

122 tongue

123 bridge

124 strain measuring sensor

125 connection cable

13 guide frame

14 washer

15 piezo force sensor

151 connection cable

16 more washers

17 lid

171 margin

172 Flaube

173 Support area

174 recess

Claims

Expectations

1. A method for detecting a person in a piece of furniture, wherein the piece of furniture has a number of sensors (10) spaced apart from one another on the piece of furniture, and at least one evaluation device to which the sensors are coupled, characterized by the following steps:

- Providing position information to each of the sensors (10);

- Measuring a force acting on each sensor (10) in each case;

- Transmitting a value corresponding to the force from each of the sensors (10) to the evaluation device; and

- Determining and outputting position information on a person lying in the furniture on the basis of the transmitted values of the force, taking into account the position information.

2. The method according to claim 1, wherein the position information includes in wel cher of the following positions or postures the person is in the Liegemö bel: lateral position, supine or prone position, sitting posture or other position.

3. The method according to claim 1 or 2, in which absolute values of the values of the force are used to determine the position information.

4. The method according to any one of claims 1 to 3, in which a difference in the values of two sensors (10) are used to determine the position information.

5. The method according to claim 4, wherein the difference between values of two sensors (10) be adjacent is formed.

6. The method according to claim 5, in which the difference is normalized over the distance between the sensors (10) taken into account.

7. The method according to any one of claims 1 to 6, in which the values of the sensors (10) are processed as a 2-dimensional image using the position information and are evaluated using image recognition methods.

8. Device for detecting a person in a piece of furniture, having a number of sensors (10) which are arranged at a distance from one another on the piece of furniture, the sensors (10) being set up to measure a force generated by one The person in the reclining furniture is exerted on the respective sensor (10) and outputting a value corresponding to the force, as well as at least one evaluation device to which the sensors (10) are coupled and which is set up to measure the values from the sensors ( 10) to detect and evaluate output values, characterized in that the at least one evaluation device is further set up to determine location information on the person in the furniture based on the values of the sensors (10), taking into account their arrangement on the furniture.

9. The device according to claim 8, wherein the sensors (10) each have a bending force sensor (12) with a strain gauge (124).

10. Apparatus according to claim 8 or 9, in which the sensors (10) can each differentiate between more than two different values for the force.

11. Device according to one of Claims 8 to 10, in which there is more than one evaluation device, a group of sensors (10) being coupled to each of the evaluation devices.

12. The device according to claim 11, wherein spatially adjacent sensors (10) are assigned to a group.