GB2207251A - Improvement in or relating to hospital beds incorporating a weighing device - Google Patents

Abstract

A bed which incorporates a mattress platform 6 supported at or below the head and foot of the bed by a plurality of support members 2, 3, 4, 5 arranged between the mattress platform and a castered base frame 1 also includes weighing devices associated with the support members. Each weighing device has an output dependent upon the load thereupon and means are provided for computing from the outputs of each weighing device the load imposed upon the weighing devices and, consequently, the weight of a patient borne by the mattress platform. The mattress platform 6 may be raised and lowered and tilted about its longitudinal axis. At one end lifting arms 2 are pivotally connected to pivot bracket 3 through a transverse axle 20. The axle is of partially open section to house two strain gauges 22 of load cells. Similar provision is made in the axle between the lifting arm 2 and pivot bracket 5 at the other end. <IMAGE>

Description

Improvements in or Relating to Hospital Type Beds This invention relates to hospital type beds, and more especially to such beds which include in situ weighing means for monitoring the weight or weight changes of a person supported by the bed.

In a preferred arrangement, the invention concerns multi-position beds such as used in hospitals and for persons who by reason of physical disability or age are unable or find it difficult to turn or move themselves in bed.

Such a bed is described and claimed in our copending Patent Application 8429324 and comprises a base frame carrying a mattress platform which is pivoted for lateral tilting at its ends on pivot brackets carried on the base frame. The platform has a centre section and two side sections which are connected at their ends by links to end pivot frames carried by the centre section and are connected at intermediate points through pairs of links to a pivot bracket whereby lateral tilting of the centre section in either direction causes a side section to tilt in the other direction to produce a turning effect upon a patient.

Whilst such beds have proved to be well capable of turning and tilting a patient to enable inter alia a patient's condition to be monitored in a variety of forms, one parameter relevant to a patient's health or treatment which, hitherto, has only been monitored with difficulty in a bed-ridden patient, is that of changes in patient's weight.

As is known, certain medical treatments require accurate measurements of a patient's weight changes over given time periods. Hitherto, where monitoring of a patient's weight has been required, the patient has been subjected to considerable disturbance and inconvenience due to the need either to move the patient or the bed occupied by the patient to a weighing station.

It is an object of the present invention to provide a bed which enables weight or changes in weight to be monitored with a minimum of discomfort and disturbance to a patient.

In accordance with one aspect of the present invention there is provided a bed incorporating a mattress platform and a plurality of support members -arranged to be disposed between the mattress platform and the ground at or below the head and foot of the bed; weighing devices associated with the support members each having an output dependent upon the load thereupon; and means for computing from the outputs of each weighing device the load imposed upon the weighing devices and, consequently, the weight of a patient borne by the mattress platform.

In accordance with another aspect of the invention there is provided a multi-position bed of the kind hereinabove referred to and which incorporates a mattress platform supported above a base frame, the bed including support members positioned between the mattress platform and the base frame and incorporating weighing devices, each of said weighing devices having outputs related to the load thereabove, and a display operable to provide a weight reading dependent upon the outputs from each of the weighing devices indicative of the weight of a patient borne by the mattress platform.

By means of the invention, it is possible to provide regular monitoring of the weight of a patient confined to bed.

So as to reduce the "dead weight" in the outputs from each of the weighing devices, the weighing devices are preferably located at as high a position in the bed structure as can reasonably and conveniently be arranged. Thus in a multi-position bed of the kind hereinabove described, the weighing devices may comprise load cells connected in the pivot pins or axles associated with pivot brackets for accommodating various tilting movements of the bed.

In a non-tilting conventional bed, the weighing devices would be positioned adjacent suitable load points.

In one embodiment of the invention, a bed according to the invention may incorporate four weighing devices, two on each side of the longitudinal centre line of the bed at or adjacent to the head of the bed and two on each side of the said longitudinal centre line at or adjacent to the foot of the bed.

With a multi-position bed of the kind hereinabove described, the four weighing devices can comprise load cells located at pivot points on each side of hinge brackets at the foot and head of the bed.

In order that the invention may be more readily understood one embodiment thereof will now be described by way of example with reference to the accompanying drawings in which: Figure 1 is a side elevation of a multipositional bed incorporating the invention; Figure 2 is an end elevation of the bed of Figure 1; Figure 3 is an end sectional elevation to an enlarged scale showing the disposition of a weighing device in the foot end of the bed illustrated in Figure 1.; and Figure 4 is an end sectional elevation to an enlarged scale showing the disposition of a weighing device in the front end of the bed illustrated in Figure 1.

Referring firstly to Figures 1 and 2 of the drawings, the bed comprises a base frame 1 supported on casters and having two pairs of lifting arms 2 connected each at one end to the base frame for pivotal movement. The ends of one pair of lifting arms 2 remote from the base frame 1 are in turn connected for pivotal movement to a pivot bracket 3 dependent from a support member 4 carried by a centre section 6 of a mattress platform. The ends of the other pair of lifting arms 2 remote from the base frame 1 are connected for pivotal movement to a pivot bracket 5.

The pivot brackets 3 and 5 act as pivot supports for the centre section 6 of the mattress platform.

The mattress platform includes two lengthwise extending side sections 7. These side sections 7 are not hinged directly to the centre section 6 but simply include two interengaging features in the form of side frame registers 11 comprising pins and slots which simply act to steady and hold the centre and side sections in the position shown in Figure 2. When the bed is used as a turning bed, the members 11 disengage.

The side sections 7 are carried by pairs of links 8, 9 which join the pivot brackets 3 and 5 to the side sections 7 at points below and roughly mid-way across the side sections.

The side sections 7 are also connected at each end of the bed by side frame pivot arms 13 to an end pivot frame 12 the pivot frame 12 being rigidly connected to the centre bed section 6. Movement of the bottom links 8 is restricted in a downward direction, by bottom link stops 10.

By appropriate operation of an electric turning drive motor 16, the centre section 6 turns about its pivot to laterally tilt the centre section therby producing a turning effect on a patient lying on the mattress of the bed.

Raising and lowering of the mattress platform is effected by the lifting arms 2 in operation of electric motors 14. Operation of both motors 14 will cause lifting or lowering of the mattress platform, whilst operation of one or the other will cause tilting longitudinally of the bed in one direction or the other.

The multi-position bed described above is, as already mentioned, the subject of our co-pending Patent Application 84.29324 and is more fully described and disclosed therein.

Turning now to the features illustrated in Figure 3, it will be seen that the lifting arms 2 are pivotally connected to the pivot bracket 3 through a transverse axle 20 which extends between and passes through the adjacent knee joints of both the arms 2 and the lower connecting pieces 21 of the pivot bracket. The transverse axle 20 is partially of open section to house strain gauges 22 of load cells. The gauges 22 measure the strain applied at the two knee joints and transmit representative electronic signals via a cable 23 to a monitor located on or positioned close to the bed. The pivot bracket 3 is cast as a closed section to provide the required structural rigidity to prevent the occurance of lateral strains.

As will be seen from Figure 4, similar strain gauges 25 are housed within a transverse axle 26 extending between the respective knee joints of the front pair of lifting arms 2 and the pivot bracket 5.

The electronic signals from each load cell are summed and averaged to provide an accurate measurement of the weight of that part of the bed structure above the respective knee joints and a patient positioned on the bed. From this average, the weight of the patient can readily be deduced and displayed as required.

It will be appreciated that the monitoring device can be arranged to take account of any tilting disposition of the bed during weighing. Preferably, however, for weighing purposes the bed is in a fully horizontal position and at a predetermined height above the ground, so that any variable factors associated with different dispositions and load and frictional relationships are negated between separate weighing operations.

By means of the invention as particularly described we have provided a multi-position bed capable additionally of providing a regular and consistent weight monitoring operation with respect to a patient on that bed.

Claims (7)

CLL S:

1. A. bed incorporating a mattress platform and a plurality of support members arranged to be disposed between the mattress platform and the ground at or below the head and foot of the bed; weighing devices associated with the support members each having an output dependent upon the load thereupon; and means for computing from the outputs of each weighing device the load imposed upon the weighing devices and, consequently, the weight of a patient borne by the mattress platform.

2. A multi-position bed which incorporates a mattress platform supported above a base frame, the bed including support members positioned between the mattress platform and the base frame and incorporating weighing devices, each of said welching devices having outputs related to the load thereabove, and a display operable to provide a weight reading dependent upon the outputs fro each of the weighing devices indicative cf the weicht of a patient borne by the rat tress platform.

3. A bed as claired in Claim 2 wherein the weighing devices comprise load cells connected in pivot pins or axles associated with pivot brackets for accommodating various tilting roverents of the bed.

A A bed as claimed in Claim 1 wherein the weighing devices are positioned adjacent suitable load points of the bed structure.

5. A bed as claimed in any one of the preceding claims which incorporates two weighing devices on each side of the longitudinal centre line of the bed at or adjacent to the head of the bed and two weighing devices on each side of the said longitudinal centre line at or adjacent to the foot of the bed.

6. A bed as claimed in Claim 2 or Claim 3 which incorporates two weighing devices on each side of the longitudinal centre line of the bed and two on each side of the longitudinal centre line of the bed, the four weighing devices comprising load cells located at pivot points on each side of hinge brackets at the foot and head of the bed.

7. A multi-position bed substantially as herein described with reference to Figures l te 4 of the accompanying drawings.