Note: Descriptions are shown in the official language in which they were submitted.
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This invention concerns a bed of the kind (hereinafter termed of the kind
referred to) comprising hingedly connected sections adjustable between a flat
configuration and a generally chair-like configuration.
A serious problem in hospitals, nursing homes and similar establishments
is the development of pressure sores, particularly with the immobile and
elderly. These
can manifest in less than one hour and their subsequent treatment can be
lengthy and
costly.
The present invention is based on the discovery that quite small adjustments
in the configuration of a bed of the kind referred have the effect of
significantly moving
the positions of maximum pressure between an occupant of the bed and the bed
mattress.
According to the present invention, there is provided a bed comprising a
plurality of hingedly connected sections, characterised by means automatically
to adjust
the configuration of the sections of the bed at periodic intervals.
The bed may comprise three sections, a back-rest section, a central section
and a foot-rest section.
The configuration of the bed may be controlled by a microprocessor.
The configuration of the bed may adjust in accordance with a selected one
of a number of predetermined programmes.
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The configuration of the bed may adjust in accordance with an operator
generated programme.
The bed may incozporate pressure sensors at critical parts of the body prone
to pressure sores of an occupant of the bed, there being means for comparing
sensed
pressures and the durations thereof with reference data to determine when the
occupant
is at risk of developing a pressure sore and means for adjusting the
configuration of the
bed when such risk is determined to mitigate the risk.
Each pressure sensor may comprise an array of strain gauges carried by a
mat-like support.
The mat-like support may be located on, within or below the mattress.
There may be three sensors located in the vicinity of the heels, sacrum and
shoulders of an occupant of the bed.
Motors may be provided for adjusting the configuration of the bed.
The invention will be further apparent from the following description with
reference to the several figures of the accompanying drawings, which show, by
way of
exampie only, one form of bed embodying same.
Of the drawings:-
Figure 1 shows a side view of the bed; and
Figures 2-5 show possible different configurations
for the sections of the bed.
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Referring firstly to Figure I, it will be seen that the bed comprises a
rectangular base frame 10 which mounts ground engaging castor wheels 11, at
least two
of which can be immobilised by a brake pedal 12 to prevent unwanted movement
of the
bed over the floor.
Above the base frame 10 is a sub-frame 14 connected with the base frame
by four (two on each side) bell-crank levers 15, whose centre pivots are
connected to
posts I6 extending upwardly from the base frame 10 and whose upper ends are
pivotally
connected at 17 to the sub-frame 14.
The lower end of the lever I 5 at the head of the bed is connected with the
lower end of that at the foot of the bed by a link 18 and linear motor 19.
A further linear motor 20 drives a link 21 pivotally connected between a
post 22 extending upwardly from the base frame 10 and the link 18 to move the
lower
arms of the bell-crank levers 15 forwardly or backwardly in the direction of
the arrows
X to raise or lower the sub-frame 14 relative to the base frame 10.
Above the sub-frame 14 is the bed itself comprising three hingedly
connected sections, a back-rest section 30, a central section 31 and a foot-
rest section 32,
all of which support a mattress 33 (or mattress sections connected together by
slide
fasteners).
The back-rest section 30 is pivotally connected with the sub-frame 14 at
34. A bell-crank lever 35 has its centre pivotally connected with the sub-
frame 14 at 34,
and the distal end of its rear limb pivotally connected with the hinge 36
between the
sections 30 and 31. A further linear motor 40 is operable to move the forward
limb of
the lever 35 fore and aft to raise and lower the back-rest section 30. It
should be noted
that raising the section 30 causes a lowering of the hinge connection 36
between the
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sections 30 and 31 and vice versa. This has the effect of preventing or
minimising
sliding movement of an occupant of the bed longitudinally therealong.
The footrest section 32 is connected with the sub-frame 14 by a pair of links
50 (one on each side) pivotally connected between the sub-frame 14 and the
hinged
connection 51 between the sections 31 and 32.
A link 52 is pivotally connected to the section 32 at its upper end, and to
the
distal end of a forward limb of a bell crank lever 53 whose centre is
pivotally connected
at 17 to the distal end of the rearward limb of the lever 15 adjacent the foot
of the bed.
A further linear motor 54 is pivotally connected with the lower limb of the
bell crank lever 53 to rotate the lever 53 about its centre to raise and lower
the section 32
relative to the hinge 51.
Operation of the linear motor I 9 causes rotation only of the rearward bell
crank lever i 5 adjacent the foot of the bed to cause the sub-frame 14 to
pivot about the
connection 17 between the sub-frame 14 and lever 15 adjacent the head of the
bed to
effect Trendenelberg movements of the bed.
Figures 2-5 show a number of possible different configurations for the
sections of the bed.
The bed is provided with a control panel 60 incorporating a
microprocessor capable of performing various functions.
Firstly, one of a number of pre-selected programmes can be selected
whereby the configuration of the bed will automatically adjust at pre-
determined
intervals in accordance with the programme parameters.
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Alternatively, an operator may enter desired ranges of permitted angular
movement for the back rest, the foot rest and Trendenelberg movement and a
time
interval desired between adjustments. The control will then effect adjustments
at the
pre-determined intervals within the pre-determined parameters on a random
basis.
Finally, when pressure sensors 70 are provided within or on the bed
mattress 33, the control may automatically adjust the bed to prevent the
incidence of
pressure levels for periods longer than those which can be tolerated without
the risk of
pressure sores.
A sub-control panel 61 on an extensible lead is provided to enable an
operator or indeed the patient to adjust the bed as desired at any time in any
of its
possible modes of movement.
The control panels include means to operate the motor 20 to raise and lower
the entire bed structure relative to the base frame to position the bed at the
most
convenient height for re-making or transferring the patient to or from the
bed.
It will be appreciated that it is not intended to limit the invention to
the above example only, many variations, such as might readily occur to one
skilled in
the art, being possible, without departing from the scope thereof.
