Patent Application
20100171622
The present invention relates to a bed with integrated sensor unit for a patient. Furthermore the invention relates to a method of providing a bed with a sensor unit for a patient.
Monitoring of patients is a standard tool in different situations, mostly in hospital settings. Depending on the diagnosis, different parameters are monitored and different monitoring techniques are known, according to which sensor units are integrated into a hospital bed or the like. Parameters that are needed often are weight, heart rate, breathing rate and breathing abnormalities, as well as special movement patterns of the patient, e.g. during sleep. It requires a significant technical effort and different techniques to measure these quantities. Especially monitoring the weight is quite expensive. For those patients, for whom weight measurements are not required, a small and inexpensive design would be more attractive. It would also be attractive to equip a bed with such a measuring apparatus on demand, i.e. only if required.
It is an object of the present invention to provide a simple and reliable technique for monitoring patients in a bed.
The object of the present invention is achieved by a bed for a patient, comprising a bedframe with at least a first and a second bedframe section, said bedframe sections being connected to each other by means of at least one hinge, the bed further comprising a sensor unit, characterized in that the sensor unit is connected with the pivot of the hinge, and is adapted to measure the movement of a bedframe section in a direction substantially perpendicular to the rotary axis of the pivot.
This object is achieved according to the invention by a method of providing a bed for a patient with a sensor unit, said bed comprising a bedframe with at least a first and a second bedframe section, said bedframe sections being connected to each other by means of at least one hinge, the method comprising the step of replacing the original pivot of the hinge with a substitutional pivot, to which a sensor unit is connected, said sensor unit being adapted to measure a movement of one of the bedframe sections in a direction substantially perpendicular to the rotary axis of the pivot.
The present invention describes a design of a bed and a sensor unit. Furthermore the present invention describes a method of handling said sensor unit with said bed. A bed according to the present invention is defined as a surface or any other device to rest on or to sit on etc., e.g. a conventional bed, a hospital bed, a care bed, a couch, a conventional chair, a dentist's chair, a wheelchair, an (operating) table, etc. However, the present invention is preferably applicable in hospital and nursing home settings. Accordingly the bed is preferably a hospital bed or a care bed.
A core idea of the invention is to integrate sensor units in the hinges of the bed's bedframe, in particular on the hinges which are used to connected bedframe sections to each other. Preferably, the sensor units are integrated in the hinges of the supporting surface of the bed, since in this way the most valuable information about patient movements can be obtained in a very simple and reliable way. The integration is achieved according to the invention in a way that allows a miniaturization of the overall sensing equipment. Furthermore an on demand retrofit of the sensor unit is possible. Thus not every bed has to provide these integrated sensors units, but can be equipped with the sensor units when relevant. For example, using the present invention a normal hospital bed can easily be retrofit to obtain an intensive care bed. The retrofit can be done by care personal, no technician is required. Additionally, the suggested integration of the sensor units does not restrict the overall design of the bed in terms of flexibility and moving parts. Furthermore, this solution can be realized at low cost.
The present invention is not limited to a certain type of sensor element. The sensor element of the sensor unit can be for example a force sensitive, pressure sensitive, or acceleration sensitive sensor element, etc. The sensor element may work based on capacitive measurements, piezoelectric measurements, seismic measurements, gyroscopic measurement, etc. The sensor element can also be a hydraulic element connected to a pressure sensor or the like.
These and other aspects of the invention will be described in detail hereinafter, by way of example, with reference to the following embodiment and the accompanying drawings; in which:
Design and position of a sensor unit 5 according to a first embodiment of the invention are illustrated in
The bore hole 17 provides a slackness for the pivot 9, i.e. the diameter of the bore hole 17 is larger than the diameter of the pivot 9. This slackness does not only provide a space for rotating of the pivot 9 in the bore hole 17. Additionally the slackness is extended in a way that it allows the pivot 9 to move in a moving direction 21 perpendicular to the rotary axis 22 of the pivot 9 without forming a closed linkage (force closure) with the second bedframe section 2, if the movement of the first bedframe section 1 does not exceed a limit value. In other words, the first bedframe section 1 can move perpendicular to the rotary axis 22 of the pivot 9, i.e. horizontally with respect to the operating position of the hospital bed, without being in direct contact with the second bedframe section 2.
On the portion 23 of the pivot 9, which extends beyond the inner leg 15 of the U-shaped connector 11, an U-shaped support 24 is rigidly fixed. The U-shaped support 24 is spaced well apart from the outer hinge 4. The other end 14 of the pivot 9 ends with the outer leg 25 of the U-shaped support 24. In-between the outer leg 25 and the inner leg 26 of the U-shaped support 24 an arm 27 of a support member 28 is positioned. The arm 27 of the support member 28 comprises a bore hole 29, which receives a part of the extended portion 23 of the pivot 9. The side surfaces 31 of the arm 27 of the support member 28 are guided by the inner surfaces 32 of the two legs 25, 26 of the U-shaped support 24. To the arm 27 of the support member 28 a clamping device 33 is connected. The clamping device 33 is adapted to connect the support member 28 to the front side 39 of the first bedframe section 1.
The bore hole 29 provides a slackness for the pivot 9, i.e. a space for rotating of the pivot 9 in the bore hole 29. The bore hole 29, which preferably is provided with an oil film or the like, is adapted such that the pivot 9 can also perform very small movements in a direction perpendicular to the rotary axis 22 of the pivot 9. However, the slackness of the bore hole 29 is significant smaller than the extended slackness of the bore hole 17 of the connector arm 11.
To the base element 35 of the U-shaped support 24 the sensor unit 5 is connected. The sensor unit 5 comprises a force sensitive sensor element 36. Between the sensor element 36 and the front side 34 of the second bedframe section 2 a resilient element in form of a spring 38 is provided. The spring 38 is in working contact with the sensor element 36 on the one hand and rests against the front side 34 of the second bedframe section 2 on the other hand. Thus, the spring 38 ensures a permanent contact of the sensor element 36 with the second bedframe section 2. This permanent contact is supported by an adjustment tool, e.g. in form of an adjusting ring (not shown), which is located between the sensor unit 5 and the base element 35 of the U-shaped support 24. By means of the adjusting ring an initial tension is provided to the spring 38. Alternatively the initial tension of the spring 38 results solely from the spring characteristics and no adjusting ring is used. Because of the initial tension of the spring 38, the slackness of the bore hole 29 is factual abrogated, i.e. the U-shaped support 24 is in direct contact with the pivot 9. Instead of a spring, another resilient element can be used, e.g. a rubber disk.
With the outer hinge 4 as described above the two bedframe sections 1, 2 can rotate with respect to each other in rotating direction 42 around the rotary axis 22 of the pivot 9. The sensor unit 5 and/or the spring 38 is adapted in a way, that in all rotary positions the sensor element 36 of the sensor unit 5 is in permanent pretensioned contact with the corresponding front side 34 of the second bedframe section 2. For example the spring can obtain the form of a spherical shaped hood, which is imposed on the sensor element 36 and which rests against the front side 34 of the second bedframe section 2 in a way that ensures a permanent contact of the sensor element 36 with said second bedframe section 2 in all rotary positions.
The sensor unit 5 is connected to the first bedframe section 1 via the support member 28 and the pivot 9 of the hinge 4 is in a fixed rigid position. With this an exactly defined measuring position of the sensor unit 5 is guaranteed. Since the sensor unit 5 is rigidly coupled to the pivot 9 and the pivot 9 is guided in the bore hole 29 of the arm 27 of the support member 28, which is rigidly fixed to the first bedframe section 1, a movement ΔX of the first bedframe section 1 in a moving direction 20 substantially perpendicular to the rotary axis 22 of the pivot 9 leads to a corresponding movement ΔX of the extended portion 23 of the pivot 9 and thus to a corresponding movement ΔX of the sensor unit 5 relative to the second bedframe section 2, see
Design and position of a sensor unit 5′ according to a second embodiment of the invention are illustrated in
The bore holes 17′ provide a slackness for the pivot 9, i.e. the diameter of the bore holes 17′ are larger than the diameter of the pivot 9. This slackness does not only provide a space for rotating of the pivot 9 in the bore holes 17′. Additionally the slackness is extended in a way that it allows the pivot 9 to move in a moving direction 21 perpendicular to the rotary axis 22 of the pivot 9 without forming a closed linkage (force closure) with the first bedframe section 1, if the movement of the first bedframe section 1 does not exceed a limit value. In other words, the first bedframe section 1 can move perpendicular to the rotary axis 22 of the pivot 9, i.e. horizontally with respect to the operating position of the hospital bed, without being in direct contact with the second bedframe section 2.
An U-shaped support 24, which is spaced well apart from the outer hinge 4, comprises two legs 25, 26. Each leg comprises a bore hole 29′, which receives a part of the extended portion 23 of the pivot 9, which extends beyond the inner leg 15 of the U-shaped connector 11. The other end 14 of the pivot 9 ends with the outer leg 25 of the U-shaped support 24. In-between the outer leg 25 and the inner leg 26 of the U-shaped support 24 an arm 27 of a support member 28 is positioned. The arm 27 of the support member 2 is rigidly fixed to the pivot 9. The side surfaces 31 of the arm 27 of the support member 28 are guided by the inner surfaces 32 of the two legs 25, 26 of the U-shaped support 24. To the arm 27 of the support member 28 a clamping device 33 is connected. The clamping device 33 is adapted to connect the support member 28 to the front side 34 of the second bedframe section 2.
The bore holes 29′ provide a slackness for the pivot 9, i.e. a space for rotating of the pivot 9 in the bore holes 29′. The bore holes 29′, which preferably are provided with an oil film or the like, is adapted such that the pivot 9 can also perform very small movements in a direction perpendicular to the rotary axis 22 of the pivot 9. However, the slackness of the bore holes 29′ is significant smaller than the extended slackness of the bore hole 17′ of the legs 13, 15 of the connector 11.
To the base element 35 of the U-shaped support 24 the sensor unit 5 is connected. The sensor unit 5 comprises a force sensitive sensor element 36. Between the sensor element 36 and the front side 39 of the first bedframe section 1 a resilient element in form of a spring 38 is provided. The spring 38 is in working contact with the sensor element 36 on the one hand and rests against the front side 39 of the first bedframe section 1 on the other hand. Thus, the spring 38 ensures a permanent contact of the sensor element 36 with the first bedframe section 1. This permanent contact is supported by an adjustment tool, e.g. in form of an adjusting ring (not shown), which is located between the sensor unit 5 and the base element 35 of the U-shaped support 24. By means of the adjusting ring an initial tension is provided to the spring 38. Alternatively the initial tension of the spring 38 results solely from the spring characteristics and no adjusting ring is used. Because of the initial tension of the spring 38, the slackness of the bore holes 29 are factual abrogated, i.e. the U-shaped support 24 is in direct contact with the pivot 9.
With the outer hinge 4 as described above the two bedframe sections 1, 2 can rotate with respect to each other in rotating direction 42 around the rotary axis 22 of the pivot 9. In all rotary positions the sensor element 36 of the sensor unit 5 is in permanent pretensioned contact with the corresponding front side 39 of the first bedframe section 1. The sensor unit 5 is connected to the second bedframe section 2 via the support member 28 and the pivot 9 of the hinge 4 is in a fixed rigid position. With this an exactly defined measuring position of the sensor unit 5 is guaranteed.
Since the slackness of the bore holes 29′ is abrogated by the spring 38, a movement ΔX of the first bedframe section 1 in a moving direction 20 substantially perpendicular to the rotary axis 22 of the pivot 9 leads to a decrease of the distance D between the sensor element 36 and the front side 39 of the first bedframe section 1 to D-ΔX, see
In other words, a (horizontal) force, induced by a patient lying on the hospital bed, is measured at the inner hinge, which is formed by the extended portion 23 of the pivot 9 in the bore holes 29′ of the legs 25, 26, without a direct contact to the second bedframe section 2 in the outer hinge 4. The slackness of the bore holes 17′ in the legs 13, 15 of the connector 11 preferably exceeds the maximum measuring movement of the sensor unit 5 relative to the second bedframe section 2. The slackness of the bore holes 29′ in the legs 25, 26 preferably exceeds twice the maximum horizontal movement ΔXmax of the first bedframe section 1.
A standard hospital bed can easily be retrofit to obtain an intensive care bed by providing one or more sensor units 5, 5′ to the hinges 4 between the bedframe sections 1, 2, 1′ of the bed. Preferably all hinges 4 of the hospital bed will be provided with a sensor unit 5. 5′ as described. For obtaining analysable results it is however adequate to provide a single sensor unit 5. 5′ to one hinge 4. This can be done either by replacing the original pivot of the hinge 4 with a substitutional pivot 9, to which a sensor unit 5, 5′ is already connected. In
The placement procedure of the sensor unit 5, 5′ comprises the following steps: First the original pivot is replaced by a substitutional pivot 9 or a pivot extension is connected. Subsequently a mechanical fixture, here in form of the support member 28, is connected with the bedframe section, which is not in permanent contact with the sensor element 5, 5′. Furthermore, the sensor unit 5, 5′ is adjusted to the opposite bedframe section. Finally a cable connection or a wireless communication link (not shown) is established between the sensor unit 5, 5′ and the analyzing unit.
The analyzing unit is adapted to analyze the plurality of recorded signals according to a predefined analyzing pattern. For this purpose the analysing unit preferably comprises a processing unit which is adapted for performing all tasks of calculating and computing the measured data as well as determining and assessing results. This is preferably achieved by means of a computer software comprising computer instructions adapted for carrying out said analyzing steps, when the software is executed in the processing unit. The processing unit itself may comprise functional modules or units, which are implemented in form of hardware, software or in form of a combination of both.
It will be evident to those skilled in the art that the invention is not limited to the details of the foregoing illustrative embodiments, and that the present invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein. It will furthermore be evident that the word “comprising” does not exclude other elements or steps, that the words “a” or “an” do not exclude a plurality, and that a single element, such as a computer system or another unit may fulfil the functions of several means recited in the claims. Any reference signs in the claims shall not be construed as limiting the claim concerned.
| Number | Date | Country | Kind |
|---|---|---|---|
| 06118867.8 | Aug 2006 | EP | regional |
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/IB07/53108 | 8/7/2007 | WO | 00 | 2/11/2009 |
