BED CONTROL PROCEDURE

The present invention relates to a bed assembly and in particular to a method of controlling the adjustment of the bed.

Typical modern hospital beds are adjustable into a plurality of different configurations and different heights, hi order to achieve adjustment of the bed, there is provided a plurality of electrically operated actuators. This has the advantage of being able to increase the comfort of the patient and also to be able to effect certain treatments. One such treatment is to raise the patient's legs to improve vascular flow. In order to achieve this, a foot rest portion of the bed platform and well as a thigh rest portion are raised above their lying positions. This treatment is known in the art. It is also common with such configurable beds to allow the patient control over the adjustment of the bed. For this purpose, the patient is given a key pad which is provided with a plurality of control keys allowing the patient to adjust the bed, for example to a lying position, to several preset raised configurations including as a seat, as well as infinitely variable raised positions of the back rest, thigh rest and leg rest. It has been found that allowing a patient control over the configuration of the bed significantly improves patient comfort and as a result can improve healing times.

However, in some circumstances, such as when the bed must be configured in a particular manner for treatment, allowing the patient control over the configuration of the bed risks the patient reconfiguring the bed out of the configuration necessary for that treatment. Care staff must therefore either rely on the patient not to do so, to monitor regularly the patient's position and to reconfigure the bed as necessary or to deny the patient the ability to control the bed. None of these solutions is satisfactory.

The present invention seeks to provide a bed control procedure which can avoid such disadvantages. According to an aspect of the present invention, there is provided a method of controlling the configuration of a configurable bed including the steps of providing a care staff control input including one or more control actuators operable to configure a part of the bed into a first configuration, providing a patient control input including one or more control actuators operable to adjust the configuration of the bed, wherein the patient's control input is not able to modify the first configuration set by the care staff control input.

Advantageously, the first configuration is a treatment configuration, in the preferred embodiment a legs up configuration.

This method provides for hospital staff to be able to set the bed into a specific configuration, such as a legs up configuration to improve vascular flow, and still to allow the patient control over the configuration of the bed, without losing the treatment configuration set by the hospital staff. In the example given, the patient would still have control of the back rest, for example to be able to move from a lying position to a sitting position, while the patient's legs remain raised.

In the preferred embodiment, the method includes the step of maintaining the first position during adjustment of the bed into one or more predetermined configurations of the bed. Typically, the bed control units for such beds have input keys or buttons which effect one or more predetermined bed positions. For example, there may be a bed flat key, a seat position key and so on. Such keys are typically provided on both the patient's key pad and on the care staffs key pad. Thus, in conventional systems, depression of the bed flat key would lose any existing treatment configuration. This feature in effect overrides the preset configurations to the extent that the first position is maintained irrespective of the preset configuration chosen by the patient, for instance. Thus, the bed can be automatically configured into a predetermined sitting position or a lying position, with the exception that the bed portions subject to the first configuration cannot be adjusted out of the first configuration. In other words, the setting of the first configuration in effect overrides any setting provided by a predetermined bed configuration. It is to be understood that in the preferred embodiment the first configuration may nevertheless be adjusted for patient comfort when the bed is adjusted either by the patient or by selection of one of the predetermined configurations, without losing the characteristics of the first configuration. For instance, a first configuration which raises the leg rest may set the leg rest at a particular height. This height might be ideal when the back rest is flat but not sufficient when the back rest is raised. The method therefore preferably adjusts the legs up configuration if the back rest is adjusted to take this into account (for example to raise the legs further) and then back again when the back rest is lowered.

Advantageously, the method also provides for the first configuration to be maintained even when the care staff key pad is operated in a manner not disabling the control input which set the first configuration. This is useful for situations in which hospital staff may wish to adjust the bed but not to interfere with the first setting

implemented previously. For example, one of the preset configurations could be commanded from the care staff key pad while still being controlled to maintain the first configuration. hi the preferred embodiment, the setting of the first configuration involves pressing a specific control key or a complex input. The term complex input is intended to denote more than the single depression of a single control key. Thus, this may require the pressing of two keys and/or a sequence of key presses.

In the preferred embodiment, the method provides for allowing adjustments to the first configuration, hi the example given, in a leg raised configuration, the thigh rest is tilted upwardly from a seat portion of the bed and the leg rest raised to be substantially horizontal, hi this embodiment, care staff and/or the patient may make some adjustments to the angle of the leg rest, with the thigh rest being kept in its tilted position.

According to another aspect of the present invention, there is provided a system for controlling the configuration of a configurable bed including one or more control actuators and a control unit operable to control the actuator or actuators, a care staff control input operable to command the control unit to configure a part of the bed into a first configuration, a patient control input operable to command the control unit to adjust the configuration of the bed, wherein the patient's control input is not able to modify the first configuration set by the care staff control input. According to another aspect of the present invention, there is provided a method of controlling the configuration of a configurable bed including the steps of providing a vascular configuration in which a patient's legs are in a raised position, the vascular configuration involving a raising of a thigh rest section and of a leg rest section of the bed, and providing for adjustment of the angle of the leg rest. Preferably, the method provides for adjustment of the leg rest from a substantially horizontal angle to an angle above or below the horizontal.

Existing configurable hospital beds have preset bed configurations. A preset configuration does not allow for simple adjustment of the leg rest without losing the vascular function, hi the preferred embodiment, however, the vascular setting, however, is not overridden or disabled when the leg rest angle is adjusted, such that it can be assured that the patient remains in the vascular position even if the bed configuration is changed.

Advantageously, the method provides for a specific input command for effecting the vascular configuration, which command retains the vascular configuration irrespective of any other control input effected by the care staff or patient.

According to another aspect of the present invention, there is provided a system for controlling the configuration of a configurable bed including a control unit providing a vascular setting in which a patient's legs are in a raised position, the vascular setting involving a raising of a thigh rest section and of a leg rest section of the bed, the control unit providing for adjustment of the angle of the leg rest while in the vascular setting.

According to another aspect of the present invention, there is provided a bed assembly operable by a method or including a system as specified herein.

Embodiments of the present invention are described below, by way of example only, with reference to the accompanying drawings, in which:

Figure 1 is a perspective view of a part of an embodiment of configurable bed; and

Figure 2 is an example of a control assembly for use in controlling the operation of the bed of Figure 1.

Referring to Figure 1, there is shown part of an embodiment of bed assembly 10 which includes a wheeled base 12 provided with four castors 14, a sub-frame 16 and mattress support frame 18. The sub-frame 16 supports a plurality of electrically operated actuators 20, 22 (only two of which are shown in Figure 1) which provide for raising and lowering of the bed 10 and for raising and lowering of the configurable sections of the mattress support frame 18. The sub-frame 16 and the mattress support frame 18 can be of a type known in the art or of a type disclosed in the applicant's co-pending British patent applications filed on the same date as the present application.

The sub-frame 16 can be raised from the lowered position shown in Figure 1 by means of two actuators (not visible in Figure 1). The mattress support frame 18 includes a back rest section 24, a seat section 26, a thigh rest section 28 and a leg rest section 30. In Figure 1 the back rest section 24 is shown in a raised condition, as is the thigh rest section 28. In effect, the bed is shown in a sitting configuration in Figure 1. The seat section 26 is, in this example, non-movable, that is it is fixed relative to the sub-frame 16. The back rest section 24 and the thigh rest section 28 can be moved by suitable control of their respective actuators 20, 22 from the positions shown to positions in which they are substantially parallel to the plane of the sub-frame 16, that is in a lying

configuration. Generally, the sections 24 and 28 are substantially infinitely variable through their ranges of travel.

The leg rest section 30 is shown in Figure 1 in a configuration in which its distal or foot end 32 is lowered. It is provided with an actuator (not visible in Figure 1) for raising the distal end 32, for example to set the leg rest section 30 substantially horizontal or parallel to the sub-frame 16. Such raising of the leg rest section 30 is typically carried out in conjunction with the thigh rest section 28, so the leg rest section 30 retains the chosen angle substantially at all angles of inclination of the thigh rest section 28. There is also provided a device, whether a mechanism or a control procedure, to ensure that the leg rest section 30 cannot be tilted above the thigh rest section 28 to create a patient unnatural and potentially damaging angle between the two.

The features of the bed 10 of Figure 1 disclosed above are common in the art so are not described further herein.

The bed assembly 10 is typically provided with a control unit for controlling the actuators of the bed and with a plurality of key pads for inputting commands to the control unit. A schematic diagram of an example of set is shown in Figure 2. The actuators 20, 22 and other actuators provided in the assembly 10 are coupled to a control unit 34, which could be of a type available in the art, suitably programmed to carry out the functions taught herein. A care staff key pad 36, which can also be of a type available in the art, includes a plurality of keys or push buttons 38-48 which in Figure 2 are simply shown numbered. As in known in the art, the keys 38-48 will include keys for performing height and angle adjustments to the sub-frame 16, keys for effecting particular adjustments to the angle of tilt of the sections 24 and 28 and at least one key for adjusting the angle of the section 30. There are typically also provided keys for setting the frame 18 into one or more predetermined configurations, such as in a lying configuration, in a seat configuration as shown and so on.

It is preferred also that there is provided a key for setting the frame 18 into a legs up configuration for improving vascular flow, hi such a configuration, the thigh rest 28 is tilted upwardly, as shown in Figure 1, and the leg rest 30 adjusted so that its distal end 32 is raised, preferably to be substantially parallel to the sub-frame 16 and/or substantially horizontal.

Figure 2 also shows a patient's key pad 50. Thus, a carer such as a nurse or doctor can set the bed into a particular configuration and the patient can control the bed also, for example to change the configuration for comfort. The patient's key pad 50 will typically provide most of the functions provided in the carer's key pad apart from configurations which provide particular treatment. For example, the patient might not be able to adjust the angle of inclination of the sub-frame 16.

The carers' key pad 36 is provided with a control input, described in further detail below, which can instruct the control unit 34 to configure a section 24, 28, 30 of the bed into a first configuration, for example for a particular treatment. One such configuration envisaged is a vascular flow configuration, in which the thigh rest 28 is tilted upwardly and the leg rest 30 raised so as to be substantially level. The patient key pad 50 can normally adjust the angles of the various sections of the frame 18 so that the patient can set the frame 18 into a lowered configuration to sleeping or resting and can set the frame 18 into a sitting position, for example as shown. In the preferred embodiment, the treatment configurations set by a carer via the carer's key pad 36 cannot be overridden the patient, irrespective of the settings commanded by the patient. For example, the preferred embodiment can provide a control input through the key pad 36 for improved vascular flow, in which the legs are raised, which cannot be overcome by the patient, whether or not the patient chooses to configure the frame 18 into a lying position or into a sitting position. More specifically, if a carer has set the bed 10, via the key pad 36, into a vascular position with legs raised, if the patient commands the frame 18 to be lowered for sleeping, the control unit 34 will effect the patient's command but will not remove the vascular configuration commanded by the carer, such that the back rest 24 will be lowered but the leg rest 30 will stay up, as will the thigh rest. Similarly, if the patient commands a sitting configuration of the frame 18, the back rest section 18 will rise, to the position shown in Figure 1 or to whatever angle chosen by the patient, but the leg rest section 30 will not drop to the position shown in Figure 1, instead will remain in a legs up position.

Thus, the patient retains control over the configuration of the bed 10 but without losing the treatment configuration set by the hospital staff. This will occur whether the patient has pressed one of the keys 38'-44' representative of a preset configuration of the bed or one of the keys 38'-44' which adjusts manually one or more of the sections 24, 28,

30 of the frame 18. Of course, the control unit 34 will in effect disable an input command from the patient which would go against the treatment configuration set by the carer.

It is preferred that the treatment configurations (in this example the legs up configuration) can be adjusted for patient comfort when the bed is adjusted either by the patient or by selection of one of the predetermined configurations, without losing the treatment. For instance, the legs up vascular flow configuration may raise the thigh rest 28 and the leg rest 30 by a particular amount. This might be ideal when the back rest 24 is flat but not sufficient when the back rest 24 is raised. The system therefore preferably adjusts the angle/height of the legs up configuration if the back rest 24 is adjusted to take this into account and then back again when the back rest 24 is lowered.

The control unit 34 preferably also maintains the legs up position (for example) even when the care staff key pad 36 is operated in a manner not disabling the control input which set that configuration. This is useful for situations in which hospital staff may wish to adjust the bed 10 but not to interfere with a the treatment setting implemented previously.

The treatment configuration could be implemented via a specific key 38-48 on the carer's key pad 36. Alternatively, it could be implemented by a complex input, that is by the pressing of two keys 38-48 and/or by a sequence of key presses.

The control system may include a feature which enables the angle of the leg rest 30 to be adjusted, by a carer and/or by the patient, when the legs up treatment setting is implemented. It is envisaged that the carer and/or patient could make small adjustments to the angle of the leg rest 30 for improved patient comfort and/or for improved treatment, while maintaining a legs up position. Any adjustment which maintains a legs up position will be considered small, hi other words, the configuration shown in Figure 1, where the distal end 32 of the leg rest 30 is at or below the level of the sub-frame 16 is considered not to maintain a legs up position. In this embodiment, the control unit 34 could be programmed to carry out a cyclic variation in the angle of the leg rest 30.

The variation in the angle of the leg rest 30 can be from a substantially horizontal angle to an angle above or below the horizontal. The vascular setting is not overridden or disabled when the leg rest angle is adjusted, such that it can be assured that the patient remains in the vascular position even if the bed configuration is changed.

The feature of being able to adjust the angle of the leg rest 30 in the vascular treatment may be used with the feature of maintaining the vascular function even during reconfiguration of the bed frame 18, as described above, or as a separate function usable with existing bed systems.