WO2023033746A2

WO2023033746A2 - Devices for alignment of a subject positioned on a support

Info

Publication number: WO2023033746A2
Application number: PCT/SG2022/050639
Authority: WO
Inventors: Deborah Xian Li KHOO; Wai Tung CHOW; Pravar JAIN; Ching Chiuan YEN
Original assignee: National University Health System Pte Ltd; National University Of Singapore
Priority date: 2021-09-02
Filing date: 2022-09-02
Publication date: 2023-03-09
Also published as: WO2023033746A3

Abstract

Disclosed is a device for aligning a subject (e.g. a patient) positioned on a support. The device includes a base maintained, in use, in register with the support, an upper member for contacting first part of the subject, and an adjustment mechanism for automatically adjusting a spacing between the base and upper member, to align the first part and a second part of the subject in a predetermined alignment.

Description

DEVICES FOR ALIGNMENT OF A SUBJECT POSITIONED ON A SUPPORT

Field

The present invention relates to a device for alignment of a subject positioned on a support, and an assembly comprising such a device and the support. The present invention can be used to, but is not limited to, aligning the spine of a patient on a hospital bed during a medical procedure.

Background

In many situations it is desirable to maintain alignment of a person's body for comfort and other reasons. For example, during thoracic surgical procedures it can be useful to bend the body of the patient to elevate the thoracic cage towards the surgeon. To achieve this, the hospital bed is broken - in other words, the middle of the hospital bed bends so that the head, feet or both are below the hips. This can cause post-operative discomfort or injury.

To protect the crucial cervical spine and brachial plexus nerves from injury, it can be useful to support the head and neck in relation to the torso or thorax. Previously, this has been achieved using a simple sponge, beanbag or layers of surgical drapes or toweling to prop the head and neck to an approximate neutral position. In this sense, the "neutral position" is a position of the patient body or spine such as when at rest or at a position at which there is little or no prospect of post-operative discomfort or injury.

These solutions themselves can create additional problems. The sponge and beanbag do not account for variations in the size and shape of patients, and the surgical drapes and toweling have a habit of dislodging during procedures. In each case, whatever was used to support the head and neck either achieved improper alignment where the apparatus was not the right size or shape for the particular patient, or had the potential to suddenly dislodge or move thereby resulting in movement of the patient during the medical procedure.

Similar issues were experienced when endeavouring to support other parts, such as legs and hips, of the body of the patient during medical procedures.

It would be desirable therefore to provide a device that avoids, or at least ameliorates, one or more of the above-mentioned problems or at least provides a useful alternative. Summary of invention

Disclosed herein is a device for aligning a subject positioned on a support, comprising: a base maintained, in use, in register with the support; an upper member for contacting first part of the subject; and an adjustment mechanism for automatically adjusting a spacing between the base and upper member, to align the first part and a second part of the subject in a predetermined alignment.

The adjustment mechanism may have an initial condition for positioning the device between the first part and the support, and an adjusted condition in which the spacing between the base and upper member causes alignment of the first part and the second part of the subject. The adjustment mechanism may be expandable from the initial condition to the adjusted condition, and collapsible from the adjusted condition to the initial condition.

The support may be a breakable support, and wherein the adjustment mechanism adjusts the spacing based on a breaking angle of the breakable support. The device may further comprise a control module for communicating with the breakable support to receive a signal corresponding to the breaking angle, the control module controlling the adjustment mechanism to adjust the spacing based on a breaking angle of the breakable support.

The predetermined alignment may be a neutral position of the first part and second part of the subject. The first part may be the head with the second part being the thorax, the neutral position comprising a neutral position of a spine of the subject.

The upper member may be hinged, or otherwise movably connected, to the base.

The upper member may comprise a cushioned surface on which the first part of the subject is positioned in use. The cushioned surface may comprise a support feature for reducing pressure on a portion of the first part of the subject. The subordinate feature may comprise a rounded protrusion with a central recess for receiving an ear of the subject.

The device may further comprise a resilient member connecting the base with the upper member.

The device may further comprise a side sheet, the side sheet, base and upper member together defining a volume, wherein the adjustment mechanism is disposed within the volume. The adjustment mechanism may be one of an hydraulic, pneumatic and mechanical device.

The base may comprise a non-slip surface for contacting the support in use.

Also disclosed herein is an assembly for aligning a subject, comprising: a support on which to position the subject; and a device according as described above, the upper member, in use, spacing the first part of the subject from the support.

The support may be a breakable support, a breaking angle of the breakable support being controlled by a controller, the controller also controlling the adjustment mechanism to align the first part and second part of the subject in accordance with the breaking angle.

A power source may supply power to the support and also to the device.

The base may be one of: positioned, in on the support; attached to the support; and forms part of the support.

Also disclosed herein is a cover shaped to receive a device as described above, the cover having flexible sides so the cover moves with the upper member on adjustment of a position of the upper member by the adjustment mechanism.

Advantageously, embodiments of the present device provide head and neck, or other bodily, support to subjects following changes in the configuration of the support in which they are resting. For example, the present device may support the head and neck during thoracic surgery performed with the patient lying on the operating table, or may support the head and neck during changes in configuration of a reclinable chair in an aircraft or train cabin.

Brief description of the drawings

Some embodiments of the present invention will now be described, by way of non-limiting example only, with reference to the accompanying drawings in which:

Figure 1 illustrates a patient lying on a broken operating table with a cushion under the head; Figure 2 and Figure 3 illustrates embodiments of a device in accordance with present teachings;

Figure 4 illustrates a cover of a device in accordance with present teachings;

Figures 5a and 5b show the device of Figure 3 in an adjusted or open condition;

Figures 6a and 6b show the device of Figure 4 in an adjusted or open condition;

Figures 7a and 7b show alternative embodiments of the device in accordance with present teachings in the initial and adjusted conditions respectively;

Figures 8a, 8b and 8c show progressive positions of an operating table and patient in accordance with a prior art method of attempting to maintain alignment of a patient;

Figures 9a and 9b show two positions of the patient on an operating table with the device in accordance with present teachings;

Figure 10 illustrates the use of multiple devices on an unbroken support; and

Figure 11 illustrates the use of a device to align parts of the body through rotation about the length of the body.

Detailed description

A device disclosed herein enables the automatic adjustment and alignment of parts of a subject, such as a patient lying on a hospital bed. The device is generally configured to accommodate patients of different sizes and shapes. Embodiments of the device include a soft supporting pillow mounted on a hinged rigid platform the angle of which, relative to its base, can be manipulated or adjusted to provide stability, elevation and safe alignment of, for example, the head and neck of the patient relative to the thorax. The angle of the soft supporting pillow with respect to the base may be set and the device may incorporate an orientation sensor that continually monitors elevation and provides feedback to a control system to automatically actuate an adjustment mechanism to maintain a set neutral position. The device is either attached to the support or bed, or in some cases is configured so that dislodgement of the device is inhibited - e.g. by providing a non-slip contact surface on the base so that it does not slip from the support during use. Figure 1 shows a circumstance in which a device in accordance with present teachings can be used. A subject 10 is positioned for thoracic surgery on operating bed 12. The operating bed 12 is broken along line 14 (going into the page). By breaking the bed 12, the thoracic cage is brought towards the surgeon or at least rendered more accessible. However, by breaking the bed 12 the head of the subject 10 bends downwardly. This can cause post-operative discomfort and potentially injure muscles and nerves of the patient 10.

A pillow 16 is inserted between the head of the subject 10 and bed 12 to provide some cushioning. However, the spine of the patient 10 remains bent away from the neutral, or at rest, position - in this case the position of the spine of the subject 10 if the bed 12 were flat and unbroken.

The devices disclosed herein seek to maintain a predetermined alignment of parts of the patient - e.g. the neutral position between the head neck and thorax, or along the spine - even when the support on which the subject is lying has been broken or otherwise modified. An example of such a device 100 is shown in Figure 2. The device 100 is used for aligning a subject positioned on a support - in the example of Figure 1 , the support is the hospital bed 12 and, in an aircraft or train example, the support will be the reclinable chair. The device 100 includes a base 102, and upper member 104 and an adjustment mechanism 106.

The base 102 is a flat, rigid body. In the present embodiment it is rectangular with rounded corners and edges so as not to scrape the patient or, when housed within a cover as described below, not to prematurely wear the cover. The base 102 is maintained, in use, in register with the support. In this sense, being "in register" means that the base 102 does not move relative to the support during normal usage of the support. For example, being "in register" can mean that the base 102 forms part of the support or that the base 102 is attached to the support for example by screws. In the present case, the base 102 is maintained in register with the support by a non-slip surface 108 on an underside (i.e. facing downward during use) of the base 102. Thus, the base 102 is placed on the support and the non-slip surface 108 significantly inhibits movement of the base 102 relative to the support, particularly when the head or other part of the subject is resting on the device 100.

The upper member 104 contacts a first part of the subject. In the circumstances shown in Figure 1 , the first part of the subject 10 is the head. In other circumstances, such as when performing a procedure on the upper thigh, the first part may be a foot or lower leg. For ease of illustration, the discussion hereafter will be made with reference to the head being the first part of the subject, and the neck and torso being the second part of the subject, though the skilled person will appreciate that the same teachings will apply to other parts of the subject.

As with the base 102, the upper member 104 may similarly be formed from a flat, rigid piece of material. The upper member 104 may also include a cutaway 110 or recess for receiving the adjustment mechanism 106 to enable the device 100 to be stored flat.

With further reference to Figure 2, the upper member 104 is attached to the base 102 in a manner that allows the adjustment mechanism 106 to manipulate the relative position of the upper member 104 relative to the base 102 to maintain a predetermined alignment of the head, neck and thorax of the subject. That adjustment may be through actuation of a plurality of pneumatic rods or, in the present instance, by the upper member 104 being hinged to the base 102 and inflating a member between the base 102 and upper member 104.

The adjustment mechanism 106 comprises a pneumatic pump 114 for inflating a member (air bladder 116). The air bladder 116 may be the mechanism by which the upper member 104 is hinged to the base 102. Alternatively, the hinge and bladder 116 may be separate components. Advantageously, the air bladder 116 serves as a resilient member to connect the upper member 104 to the base 102. Providing a resilient member, such as an air bladder 116, spring or other member, can provide an additional degree of flexibility and cushioning to the head of the subject. However, resilience is not strictly necessary in all embodiments given some embodiments will include a cushioned upper surface (see cushioned upper surface 112 in Figure 3) that already provides a degree of resilience to improve comfort and for adaptability of the device 100 to the specific shape and physiology of the subject. Alternatively, the adjustment mechanism may comprise a spring-loaded resistance to maintain a neutral plane of the device - e.g. the predetermined alignment. In this arrangement, the adjustment mechanism may comprise a first system for controlling a distance between the upper member and base (e.g. controlled hinge) that is locked in position on attainment of the desired spacing, and second system (e.g. a spring-loaded resistance or air bladder) to enable some soft movement about the predetermined alignment while returning the device to the predetermined alignment.

In other embodiments, the adjustment mechanism may be an hydraulic system or a mechanical system such as a scissor mechanism operated using a servomotor.

Referring to Figure 3, the upper member includes a cushioned surface 112 on which the head of the subject is positioned in use. The cushioned surface 112 may be formed from, or include, contoured memory foam to adapt to the physical attributes of the subject, or any other appropriate material.

The base forms a rounded tray 118 a peripheral edge 120 of which closely conforms to the shape of the cushioned upper member 112. Moreover, the adjustment mechanism 122 is wholly contained within the upper member 112 and base 118.

By rounding all of the outer edges and surfaces of the device shown in Figure 3, it can be readily inserted into a cover such as cover 124 shown in Figure 4. The cover 124 is shaped to receive the device and to conform to a shape of the device, and has flexible sides 126 as shown in Figures 6a and 6b. The flexible sides 126 allow the cover 124 to move with the upper member when the position of the upper member relative to the base is adjusted by the adjustment mechanism.

The present devices are automatically adjusted to maintain a predetermined set point, corresponding to a predetermined alignment of the head, neck and thorax subject. To that end, the adjustment mechanism automatically adjusts a spacing between the base 102, 118 and upper member 104, 112 to align the head and thorax of the subject in accordance with (i.e. to maintain) a predetermined alignment. There are various ways in which the predetermined alignment can be specified. For example, if the subject is lying on an unbroken, horizontal support surface when the device is inserted between the head and support surface, the predetermined alignment may be a spacing between the upper member 104, 112 and base 102, 118 that maintains the orientation of the head with respect to horizontal (or relative to some part of the support) when the support moves. In other circumstances, after insertion of the device between the head and support the adjustment mechanism may be used to expand or contract the device, moving the upper member respectively away from and towards the base, until the desired or predetermined alignment is achieved. The device will then maintain that alignment, generally again relative to the horizontal, if the support is broken.

The adjustment mechanism 106 therefore has an initial condition for positioning advice between head and support - this can be the most collapsed condition of the device, or the device after it has been expanded or collapsed to attain a predetermined alignment between the head and thorax subject. The adjustment mechanism 106 also has an adjusted condition in which the spacing between the base and upper member is adjusted to align the head and thorax of the subject in response to a change in configuration of the support - e.g. angling of the support as a whole, or breaking of the support as described with reference to Figure 1. In general, the adjustment mechanism 106 will be expandable from the initial condition to the adjusted condition and therefore be collapsible from the adjusted condition to the initial condition. While Figures 2 to 4 show devices in accordance with present teachings in an initial or collapsed condition, Figures 5a, 5b, 6a and 6b show devices in an expanded or adjusted condition. With reference to Figure 5a, the device 126 comprises an upper member 128 with cushion 130, and a rigid support plate 132 with a cutaway 134 for receiving the housing of a pneumatic motor 136 of the adjustment mechanism - the adjustment mechanism comprising the pneumatic motor 136 and air bladder 142. The pneumatic motor is mounted on a base plate 138 of the base 140. The base 140 is hinged to the upper member 128 by an air bladder 142 of the adjustment mechanism and inflation of which is controlled by the pneumatic motor 136. Operation of the adjustment mechanism to move the device 126 to the adjusted condition (which may be a single position, one of many discrete adjusted conditions, or any position along a continuum or continuous range of relative - e.g. angular or translational - positions of upper member and base) causes the upper member 128 to rotate relative to the base 140 in the direction of arrow X. Conversely, operation of the adjustment mechanism to move the device 126 back to the initial condition causes the upper member 128 to rotate relative to the base 140 in the opposite direction.

The device 126 also includes an orientation sensor 144 by detecting an orientation of one or both of the upper member 128 relative to the base 140 and all of the upper member 128 relative to horizontal or the support. Presently, the orientation sensor 144 is embedded into the upper member 128 though it may be positioned at any other appropriate location of the device 126. Given the cushion 130 will deform when the head of the patient is resting thereon, it can be useful to have the orientation sensor located on, in or relative to the contact surface of the upper member 128 (i.e. the surface of the upper member 128, or cushion 130 thereof, that will contact the head of the patient). This ensure that the orientation detected by the orientation since 144 accurately reflects the orientation of the first part of the body of the patient. In other embodiments, the orientation sensor is an orientation sensor such as a rotary encoder, goniometer, or linear encoder.

Figures 6a and 6b show the device 126, in the positions reflected in Figures 5b and 5a respectively, within a cover 146. The cover 146 is removable for sanitation. To that extent, the cover 146 may be one or more of impervious to fluids, stain resistant and capable of sterilisation. The cover 146 also includes a seal 148, presently embodied by a, or feeling the device 126 within the cover 146. As an alternative to a cover, or in addition thereto, the devices disclosed herein may comprise a side sheet or panel extending between the upper member and base. The side sheet based on upper member will therefore together define a volume. In some embodiments, the adjustment mechanism may be disposed within that volume. In other embodiments, the adjustment mechanism may be separate from the base and upper member, such as an external pneumatic pump with a tube for supplying air to, or extracting air from, the air bladder.

Figures 7a and 7b show an alternative embodiment of a device 148 in the initial condition and adjusted condition respectively. A cushion upper surface 150 of upper member 152 extends around a location 154 at which the upper member 152 is connected to the base 156. This ensures that the subject is not pinched when the adjustment mechanism adjusts the condition of the device 148. The cushioned upper member 152 is contoured to comfortably conform to the shape of the subject. The cushioned surface 150 also includes a support feature 158 for reducing pressure on a portion of the first part of the subject. In particular, the support feature 158 is shaped to reduce pressure, or distribute pressure, as desired across the first part of the subject. The present support feature 158 forms a rounded protrusion with a central recess for receiving an ear of the subject, thus transferring force to the skull around the ear. In other embodiments, the support feature may help avoid applying direct pressure to the nose, or other part, of the subject.

To further illustrate application of the device, a prior art arrangement is illustrated in Figures 8a to 8c. A patient 160 is seen lying on an operating table 162 with the head 164 of the patient 160 supported by a sponge 166. The broken line 168 in Figure 8a (lateral decubitus position) shows the neutral position of the head, neck and torso. When the bed is broken as shown in Figure 8b, the broken line 168 bends, showing that the head, neck and torso are no longer aligned. To rectify this issue, as shown in Figure 8c, a stack of towels 170 may be inserted between the head 164 and operating table 162. However, this arrangement is highly unstable and is only appropriate provided the operating table 162 remains in the position shown - i.e. if the operating table 162 is further adjusted, the head, neck and torso will no longer be in alignment despite the presence of the stack of towels 170. In addition, this method of alignment is reactive - the stack of towels 170 is only inserted once the patient is out of alignment.

Figures 9a and 9b show an arrangement in accordance with present teachings. When the patient 172 is positioned on the operating table 174 a device 176 in accordance with present teachings (in a deflated, initial condition) is inserted between the head 178 and operating table 174 - Figure 9a. Again, the broken line 180 shows that the head, neck and torso of the patient are properly aligned. The support, operating table 174, is breakable as shown in the transition from Figure 9a to Figure 9b - the latter shown the flexed or broken condition of the operating table. The adjustment mechanism of the device 176 adjusts the spacing between the base and upper member based on a breaking angle a of the breakable support. In particular, as the operating table 174 flexes, the air bladder (or air cushions) in the device 176 progressively inflate to maintain the predetermined alignment of the patient 172. The “predetermined alignment” in this context may not be the exact same alignment as that of the patient in the decubitus position, but is sufficiently close to that alignment to avoid causing injury or lasting discomfort of the patient 172 on completion of the thoracic procedure. Moreover, the device 176 is inflated or adjusted by an amount that depends on the amount of flexion (the breaking angle) in the table 174. Notably, the breaking angle a in Figure 9a is 90°. In some cases, the adjustment mechanism may spacing based on a breaking angle p which, in Figure 9a, is 180°.

The adjustment mechanism may adjust the spacing between the base and upper member based on an angle detected by an orientation sensor such as orientation sensor 144 of Figure 5b. Readings from the orientation sensor are sent to a control module 182 (shown in broken lines in Figure 9b) that controls operation of the adjustment mechanism based on those readings. In these embodiments, where the orientation sensor is simply detecting motion of the head 178, the orientation sensor will likely only be capable of detecting angle a (which includes proxies or equivalents for that angle, such as 90°- a, the same comments applying to angle P). In other embodiments, the control module 182 may be configured to communicate with the breakable support 174. It is particularly the case where the breakable support is power operated. In such cases, the control module 182 can receive a signal from the support 174 (which includes from a remote source that receives a signal from the support 174 or corresponding to a breaking angle of the support 174) corresponding to the breaking angle, the control module 182 then controlling the adjustment mechanism to adjust the spacing between the base and upper member of the device 176 based on the breaking angle of the breakable support 174. Moreover, the orientation sensor may monitor the relative position of, or spacing between, the upper member and base of the device 176 and provide feedback to the control module 182 to ensure the predetermined alignment of the subject is maintained.

Communication between the control module 182 and the support 174 may be through wireless connection, or wired connection if the device 176 plugs into the support 174. Moreover, the support 174 may include module 184 for detecting the breaking angle and communicating the breaking angle to the control module 182. Moreover, particularly where the device 176 is connected to the support 174 by a wired connection, the device 176 may also derive power from the same power source 186 that powers the support 174. While the device 176 may be supplied separately of the support 174, in some embodiments the device 176 may, together with the support 174 on which to position the subject 172, form part of an assembly for aligning the subject, e.g. during a surgical procedure. Thus, in use, the device will space the first part (presently the head, as illustrated in Figure 9a) of the subject 172 from the support 174. The breaking angle of the support may be controlled by a controller (e.g. module 184) that that also controls the adjustment mechanism of the device to align the first part and second part of the subject in accordance with the breaking angle. Control of the device may be effected through direct control of the adjustment mechanism by the controller of the support or by communication from the controller of the support with a control module of the device that then controls the adjustment mechanism. Moreover, the device may be capable of being switched ON and OFF as desired.

To reduce the risk of electrocution, the device and all external-facing components may be fabricated from non-conductive material. The material may be cleanable - e.g. wipe-able and/or sterilisable. The material may, as needed, be formed from tear-resistant, durable material and be, or be coated in, a non-slip material.

In a further example, multiple devices 1000 may be used together as shown in Figure 10. The devices 1000 may operate in unison to maintain a predetermined alignment along the body 1002 of the subject 1004. Alternatively, individual devices 1000 may alignment different parts of the body 1002 as desired for a particular procedure or investigation.

In a further example, the device 1100 may be placed to roll the body 1102 of the subject 1104 as shown Figure 11. In this sense, the first part and second part of the body 1102 may still be aligned along the length of the body (i.e. from head to foot), for example by using multiple devices disposed along the length, or a longer, single device. Alternatively, the first part and second part may be the left hip and right hip, left and right sides of the torso and so on - i.e. alignment laterally across the body rather than longitudinally, along the body.

Many modifications will be apparent to those skilled in the art without departing from the scope of the present invention.

In this specification and the claims that follow, unless stated otherwise, the word "comprise" and its variations, such as "comprises" and "comprising", imply the inclusion of a stated integer, step, or group of integers or steps, but not the exclusion of any other integer or step or group of integers or steps. References in this specification to any prior publication, information derived from any said prior publication, or any known matter are not and should not be taken as an acknowledgement, admission or suggestion that said prior publication, or any information derived from this prior publication or known matter forms part of the common general knowledge in the field of endeavour to which the specification relates.

Claims

1. A device for aligning a subject positioned on a support, comprising: a base maintained, in use, in register with the support; an upper member for contacting first part of the subject; and an adjustment mechanism for automatically adjusting a spacing between the base and upper member, to align the first part and a second part of the subject in a predetermined alignment.

2. The device of claim 1 , wherein the adjustment mechanism has an initial condition for positioning the device between the first part and the support, and an adjusted condition in which the spacing between the base and upper member causes alignment of the first part and the second part of the subject.

3. The device of claim 2, wherein the adjustment mechanism is expandable from the initial condition to the adjusted condition, and collapsible from the adjusted condition to the initial condition.

4. The device of any one of claims 1 to 3, wherein the support is a breakable support, and wherein the adjustment mechanism adjusts the spacing based on a breaking angle of the breakable support.

5. The device of claim 4, further comprising a control module for communicating with the breakable support to receive a signal corresponding to the breaking angle, the control module controlling the adjustment mechanism to adjust the spacing based on a breaking angle of the breakable support.

6. The device of any one of claims 1 to 5, wherein the predetermined alignment is a neutral position of the first part and second part of the subject.

7. The device of claim 6, wherein the first part is the head and the second part is the thorax, the neutral position comprising a neutral position of a spine of the subject.

8. The device of any one of claims 1 to 7, wherein the upper member is hinged to the base.

9. The device of any one of claims 1 to 8, wherein the upper member comprises a cushioned surface on which the first part of the subject is positioned in use.

10. The device of claim 9, wherein the cushioned surface comprises a support feature for reducing pressure on a portion of the first part of the subject.

11. The device of claim 10, wherein the support feature comprises a rounded protrusion with a central recess for receiving an ear of the subject.

12. The device of any one of claims 1 to 11 , further comprising a resilient member connecting the base with the upper member.

13. The device of any one of claims 1 to 12, further comprising a side sheet, the side sheet, base and upper member together defining a volume, wherein the adjustment mechanism is disposed within the volume.

14. The device of any one of claims 1 to 13, wherein the adjustment mechanism is one of an hydraulic, pneumatic and mechanical device.

15. The device of any one of claims 1 to 14, wherein the base comprises a non-slip surface for contacting the support in use.

16. An assembly for aligning a subject, comprising: a support on which to position the subject; and a device according to any one of claims 1 to 15, the upper member, in use, spacing the first part of the subject from the support.

17. The assembly of claim 16, wherein the support is a breakable support, a breaking angle of the breakable support being controlled by a controller, the controller also controlling the adjustment mechanism to align the first part and second part of the subject in accordance with the breaking angle.

18. The assembly of claim 16 or 17, wherein a power source supplies power to the support and also to the device.

19. The assembly of any one of claims 16 to 18, wherein the base is one of: positioned, in on the support; attached to the support; and forms part of the support.

20. A cover shaped to receive a device according to any one of claims 1 to 15, the cover having flexible sides so the cover moves with the upper member on adjustment of a position of the upper member by the adjustment mechanism.

15