Reconfigurable support structure

Abstract

The reconfigurable support structure 100 for providing a desired surface topography has supports, connectors 110 and fasteners (120, figure 5B). Each connector is pivotably connectable to at least two

Description

FIELD The invention relates to a reconfigurable support structure, and in particular but not exclusively to a reconfigurable support structure for use in providing support to a body part of a user. BACKGROUND Reconfigurable support structures are often used in wheelchairs to provide a support surface for the wheelchair user, for example to support the back, neck and / or head of the user. However, existing reconfigurable support structures are typically difficult for a user to manipulate into a desired configuration to provide a desired surface topography, requiring a number of parts to be held simultaneously and secured to one another. Existing reconfigurable support structures are also typically not capable of contouring to more extreme body surfaces in order to provide adequate support for a user. That can cause discomfort for a user if the support structure does not adequately conform to their body surface, particularly for individuals with conditions resulting in more extreme body surfaces. The present invention has been devised with the foregoing in mind. SUMMARY According to a first aspect, there is provided a reconfigurable support structure for providing a desired surface topography. The support structure may comprise a plurality of support elements. The support structure may also comprise a plurality of connector elements. The connector elements may connect the support elements to one another to form a continuous interconnected structure. Each connector element may be pivotably connected to at least two support elements. The connector elements and support elements may be connected to one another via an integral resilient clip. The support structure may also comprise a plurality of fasteners. The fasteners may be arranged to releasably secure the connector elements and support elements in a desired angular relationship. Previous approaches to reconfigurable support structures typically employ clamping to connect parts of the structure to one another, in the form of pairs of opposing clamp plates which are secured together (via a fastener such as a screw or bolt), with another component of the structure sandwiched between the clamp plates. Providing an integral resilient clip to connect the support elements to the connector elements may enable the components of the support structure to remain connected even without fasteners acting to secure the components in place, unlike known systems which require pairs of clamping plates. That may also reduce a total number of components in the support structure by providing a single connector structure rather than a pair of clamping plates. That may also improve ease of use, avoiding clamping plates coming apart inadvertently when fasteners are released, and allowing the support structure to be built prior to being sent to a user. That may also allow the support structure to be more easily manipulated by a user to obtain a desired surface topography by reducing a number of components needed to be held or secured by a user when fastening the components together. The support structure may more simply be formed into a desired configuration and then the components locked in a desired angular relationship using the fasteners. Each connector element may comprise a resilient clip configured to receive a part of a support element. Each support element may comprise a resilient clip configured to receive a part of a connector element. The resilient clip may be or comprise a snap-fit connection. A snap-fit connection may provide a simple and convenient approach for connecting the support elements to the connector elements, which in turn may reduce complexity and cost of manufacturing the support structure. Each fastener may be arranged to engage multiple connector elements to releasably secure the connector elements and support elements in a desired angular relationship. Each support element may comprise a substantially closed loop structure forming a perimeter surrounding an aperture of the support element. That may reduce a mass or weight of the support structure whilst providing a desired surface topography. Each connector element may be pivotably connected to respective perimeters or outer edges of the at least two support elements. Each connector element may be configured to pivot about the respective perimeters of the at least two support elements. Each connector element may be configured to pivot about a rotational axis defined by the respective perimeters of the at least two support elements. That may provide a stiffer and stronger connection between the support elements and the connector elements that provides substantially the same mechanical performance regardless of rotational position of the connector element about the support elements, unlike a multi-directional pivoting connection (such as a ball joint). That may allow the support structure to have sufficient strength and rigidity to be used and mounted in place in use without any additional supports to retain the desired surface configuration, once the fasteners secure the connector elements and support elements in the desired angular relationship. Each fastener may be at least partially located in an aperture of one of the support elements to releasably secure the connector elements and support elements in a desired angular relationship. Each connector element may extend into or be at least partially disposed in the respective aperture of the support elements to which it is connected. A fastener may be received through the respective aperture of a support element to secure a plurality of connector elements to that support element. A single fastener securing a plurality of connector elements may reduce a total number of components of the support structure and improve ease of use. The fastener may be received through the respective aperture of a support element to engage with a plurality of connector elements connected to that support element. The fastener may be arranged to engage an external surface of each connector element connected to the support element. That may enable the fastener to abut the resilient clip when the fastener is received through the aperture of the support element, which may prevent the resilient clip from releasing whilst the fastener is received through the aperture (regardless of whether the fastener has secured the support elements and the connector elements in a desired angular relationship). The fastener may be arranged to engage the external surface of each connector element connected to the support element without passing through any of the connector elements. That may reduce a need to provide apertures through the connector elements to receive the fastener, which may reduce complexity and cost of manufacturing the support structure. Alternatively, the fastener may be received through the respective aperture of a support element to engage with the support element. The fastener may be arranged to engage an external surface of the support element. The external surface of the support element may be a surface of the perimeter adjacent the aperture of the support element. Each connector element or support element may comprise a recessed portion on its external surface configured to receive at least a part of the fastener when the fastener engages the connector element or the support element. That may improve strength and rigidity of the support structure when formed into a desired surface configuration, by providing additional mechanical support to the fasteners to secure the connector elements to the support elements. Each connector element or support element may comprise a notched groove on its external surface. The notched groove may be configured to receive a corresponding surface or protrusion of a fastener. The fasteners may be configured to exert a radial or lateral force when engaged with the connector elements or the support element. The fastener may be configured to exert a force in the plane of the support element to secure the connector elements and support elements in a desired angular relationship. The fastener may be configured to radially expand when in a fastened state. The radial or lateral force may be in addition to a longitudinal or axial force exerted by the fasteners. That may improve a stiffness of each connection to prevent relative rotation between the connector elements and the support elements when the fasteners are secured, improving a strength and rigidity of the support structure to retain the desired surface configuration. Each fastener may comprise one of a bolt and nut, a clamp mechanism, a grub screw or set screw, a strap or tie member. Each connector element may comprise a substantially linear structure comprising a first end and a second end. Each connector element may be pivotably connected to each of the at least two support elements via a hooked portion. The hooked portion may be provided on the connector element. That may provide a simple, convenient structure for connecting the connector elements to the support elements and allowing for relative pivoting motion. The hooked portion may form an integral resilient clip of the connector element. That hooked portion may therefore provide a simple structure whilst performing multiple functions, including acting as a resilient clip and enabling relative pivoting motion. Each connector element may be releasably or removably connectable to the at least two support elements. The plurality of support elements and plurality of connector elements may each comprise complementary engagement features to locate the connector elements on the support elements when connected to one another. That may assist in keeping the connector elements and support elements aligned when not secured in a desired angular relationship by the fasteners (for example, whilst forming a desired surface topography), and may also provide the structure with additional strength and rigidity to retain a desired surface topography when the connector elements and support elements are secured in a desired angular relationship by the fasteners. The complementary engagement features may be or comprise a male feature and a female feature, such as a tongue and a groove. Each of the plurality of support elements may be substantially identical to one another. Each of the plurality of connector elements may be substantially identical to one another. That may reduce a number of different components required and minimise complexity and cost of manufacturing the support structure, without sacrificing flexibility of the support structure to provide a variety of different surface topographies. Each support element may comprise a mounting portion configured to enable additional components to be secured to the support element. The mounting portion may be located at a vertex of the support element. That may increase functionality of the support structure, without interference with the ability of the support structure to provide a desired surface topography. The support structure may further comprise one or more contact portions mounted on one or more of the support elements. The support structure may further comprise one or more force and / or pressure sensors. The one or more force and / or pressure sensors may be mounted on one or more of the support elements. That may enable the support structure to provide information to a user regarding a force and / or pressure distribution across the support surface in use. That may enable a user to assess if the support structure is correctly conformed or fitted to a body surface of the user. Each support element may comprise a substantially planar structure. Each support element may comprise a polygonal structure. Each support element may comprise a triangular structure. The plurality of triangular support elements may be connected via the connector elements to form a plurality of articulated hexagonal structures. That may enhance the flexibility of the support structure to provide a wider variety of different surface topographies and may enable the support structure to easily conform to more extreme surfaces (for example, body surfaces). Each articulated hexagonal structure may consist of six triangular support elements. Each triangular support element in the articulated hexagonal structure may be connected to each of the two neighbouring triangular support elements in the articulated hexagonal structure via a respective connector element. According to a second aspect, there is provided a reconfigurable support structure for providing a desired surface topography. The support structure may comprise a plurality of support elements. Each support element may comprise a triangular shape. The support structure may also comprise a plurality of connector elements. Each connector element may comprise a substantially linear structure. A first end of each connector element may be pivotably connected to a first support element. A second end of each connector element may be pivotably connected to a second support element. The support structure may also comprise a plurality of fasteners. The fasteners may be arranged to releasably secure the connector elements and support elements in a desired angular relationship. Providing triangular support elements and substantially linear connecting elements to form a reconfigurable support structure may enhance the flexibility of the support structure to provide a wide variety of different surface structures and may enable the support structure to easily conform to more extreme surfaces (for example, body surfaces). That may also reduce a number of different components required and minimise complexity and cost of manufacturing the support structure, without sacrificing flexibility of the support structure to provide a variety of different surface topographies. The first end and the second end of the connector element may respectively be pivotably connected to a side of the first support element and the second support element. The plurality of support elements may be connected via the connector elements to form a plurality of articulated hexagonal structures. Each articulated hexagonal structure may consist of six support elements. Each support element in the articulated hexagonal structure may be connected to each of the two neighbouring support elements in the articulated hexagonal structure via a respective connector element. The reconfigurable support structure of the second aspect may comprise one or more optional features of the reconfigurable support structure of the first aspect, and vice versa. According to a third aspect, there is provided a reconfigurable support structure for providing a desired surface topography. The support structure may comprise a plurality of support elements. The support structure may also comprise a plurality of connector elements. Each connector element may be pivotably connected to at least two support elements. The support structure may also comprise a plurality of fasteners. The fasteners may be arranged to releasably secure the connector elements and support elements in a desired angular relationship. The support structure may also comprise a plurality of contact portions configured to provide a surface for a user to contact in use. Each contact portion may be mounted on a respective support element. Providing separate contact portions mounted individually on respective support elements may allow the contact portions to be located where required on the support structure. That may enable a contact surface provided by the contact portions to be tailored to a user taking into account a desired surface topography provided by the support structure. That may also enable the contact surface to be formed in a modular fashion, allowing the contact surface to be extended or altered to accommodate or reflect any reconfiguration of the support structure in a different surface topography. Each contact portion may comprise a substantially smooth outer surface. The substantially smooth outer surface may comprise flat and / or curved regions such that the outer surface of each contact portion is substantially free from discontinuities. That may improve a comfort of the user when contacting the support structure in use. Each contact portion may comprise an external shape or perimeter substantially similar to the external shape or perimeter of the respective support element. Each contact portion may substantially cover or be substantially disposed over the respective support element. That may enable the contact portions to prevent or inhibit a user from contacting the support elements or connector elements when contacting the support structure in use, further improving a comfort of the user. Each contact portion may be configured to provide a resiliently compressible or cushioned surface for a user to contact in use. Each contact portion may be formed from or comprise a polymeric material, for example an elastomeric material, a rubber or a foam. That may further improve a comfort of the user when contact the support structure in use. The contact portion may be formed from or comprise a biocompatible material. Each contact portion may be releasably connectable to the respective support element. The contact portion may be connectable to the respective support element via a resilient clip. The resilient clip may be or comprise a snap-fit connection. Each respective support element may comprise a mounting portion configured to connect to the contact portion. The mounting portion may be located at a vertex of the support element. Each contact portion may comprise a cutaway or recess configured to allow rotational movement of the connector elements when the contact portion is mounted on the respective support element. The reconfigurable support structure of the third aspect may comprise one or more optional features of the reconfigurable support structure of the first aspect and / or the second aspect, and vice versa. According to a fourth aspect there is provided a support for a body part comprising the reconfigurable support structure of any of the first, second or third aspects. The support may be or comprise a seat, a backrest or back support, a neck support or a head support. According to a fifth aspect there is provided a wheelchair comprising the reconfigurable support structure of any of the first, second or third aspects and / or the support of the fourth aspect. Features which are described in the context of separate aspects and embodiments of the invention may be used together and / or be interchangeable wherever possible. Similarly, where features are described in the context of a single embodiment for brevity, those features may also be provided separately or in any suitable sub-combination. BRIEF DESCRIPTION OF DRAWINGS Embodiments of the invention will now be described by way of example only with reference to the following drawings in which: FIGs. 1A, IB and IC show an embodiment of a reconfigurable support structure in accordance with the present invention, in a flat configuration, desired surface topography configuration and a folded configuration; FIGs. 2A, 2B and 2C show a top view, isometric view and cross-sectional view respectively of support elements and a connector element from the support structure shown in FIGs. 1A to IC, the support elements connected to one another by the connector element; FIGs. 3A and 3D respectively show an isometric view and a side view of the connector element shown in FIGs. 1A to IC and 2A to 2C; FIGs. 4A and 4B show isometric views of a support element shown in FIGs. 1A to IC and 2A to 2C; FIGs. 5A, 5B, 5C and 5D show a plurality of connector elements secured to a support element using a bolt and nut; FIGs. 6A and 6B show exploded and connected views of a support element, connector elements and a contact portion from the support structure shown in FIGs. 1A to IC; FIGs. 7A, 7B and 7C show an articulated hexagonal structure formed by interconnected support elements and connector elements, in a flat state, folded state and a desired surface topography respectively; FIGs. 8A and 8B show another embodiment of a reconfigurable support structure in accordance with the present invention, comprising a force or pressure sensor; FIG. 9 shows an alternative resilient clip mechanism for use in the support structures shown in FIGs. 1 to 7 and FIG. 8; FIGs. 10A and 10B show another embodiment of a reconfigurable support structure in accordance with the present invention, comprising a pentagonal support element; and FIG. 11 shows another embodiment of a reconfigurable support structure in accordance with the present invention, comprising a hexagonal support element. Like reference numerals in different Figures may represent like elements. DETAILED DESCRIPTION Figures 1A, IB and IC show an embodiment of a reconfigurable support structure 100 for providing a desired surface topography. The support structure 100 comprises a plurality of support elements 105 connected by a plurality of connector elements 110 to provide a continuous network or mesh structure of interconnected components forming a support surface. The support structure also comprises a plurality of fasteners 105 to secure the support elements 105 and the connector elements 110 in a desired angular relationship. Figure 1A shows the support structure 100 in a substantially flat configuration. Figure IB shows the support structure 100 in a configuration showing one example of a desired surface topography. Figure IC shows the support structure 100 in a substantially folded configuration, for example for storage or transit of the support structure 100. In the embodiment shown, the support structure 100 also comprises a plurality of contact portions 115. Each contact portion 115 is mounted on a respective support element 105 such that the contact portion 115 provides a contact surface for a user to contact in use. However, it will be appreciated the support structure 100 may not comprise contact portions, and the support elements 105 and connector elements may instead together form a contact surface for a user to contact in use. Figures 2 to 7 show the various components of the support structure 100 and their interaction in more detail. Figures 2A, 2B and 2C show two support elements 105 coupled by a connector element 110. In the embodiment shown, each support element 105 comprises a substantially flat or planar structure. Each support element 105 comprises a substantially closed loop structure. The substantially closed loop structure is formed by a perimeter 105a surrounding an aperture 105b of the support element 105. Each support element 105 comprises a generally triangular shape or perimeter 105a. Three straight portions of the perimeter 105a are arranged to form sides of the triangular shape, and are connected to one another at their respective ends to form a closed loop structure. Each straight portion or side has a substantially circular cross-section along its length, although that is not essential and each side may comprise a substantially circular cross-section along only part of its length (for example, where the perimeter 105a is pivotably coupled to a connector element 110). Each connector element 110 comprises a substantially linear structure comprising a first end and a second end, and is pivotably connected at the first end to the perimeter 105a of a first support element 105 and at the second end to the perimeter 105a of a second support element 105. In the embodiment shown, each of the first end and the second end of the connector element 110 comprises a hooked portion 110a. Each hooked portion 110a comprises a mouth or opening 110b and a bore 110c defined by the curvature of the hooked portion 110a (shown in Figures 3A and 3B). The hooked portion 110a is configured to be received over one side of the perimeter 105a of a support element 105 to enable the connector element 110 to pivot about the perimeter 105a of the support element 105 (for example, about the longitudinal rotational axis defined locally by that side of the perimeter 105a, with a single degree of freedom). It will be apparent how the orientation of the support elements 105 relative to one another may be varied by pivoting one or both ends of the connector element 110 about the respective support elements 105. That in turn may enable a desired surface topography of the support structure 100 to be varied. The connector element 110 being configured to pivot about the perimeter of the support element 105 with a single degree of freedom may enable the strength and stiffness of the connection between the connector element 110 and the support element, once secured in a desired angular relationship using a fastener 120, to be substantially the same regardless of the rotational position of the connector element 110 relative to the support element 105. The open structure of the hooked portion 110a also acts as an integral resilient clip or snap-fit connection to releasably secure the connector element 110 to the support element 105. The opening 110b of the hooked portion 110a is sized such that the opening 110b must expand to allow the perimeter 105a of the support element 105 to pass through the opening 110b. Elastic deformation of the hooked portion 110a can be used to expand the size of the opening 110b. The application of force (for example, manual application of force) in pushing the perimeter 105a through the opening 110b will cause the hooked portion 110a to elastically deform and increase the size of the opening 110b. However, the diameter of the bore 110c is larger than the width of the opening 110b. When the perimeter 105a of the support element 105 passes through the opening 110b into the bore 110c and is no longer causing the hooked portion 110a to elastically deform, stored elastic energy in the hooked portion 110a (resulting from deformation of the hooked portion 110a as the perimeter 105a passes through the opening 110b) causes the opening 110b to return to its resting size, closing around the perimeter 105a of the support element (shown in cross-section in Figure 2C). The hooked portion 110a may therefore act to releasably but securely connect the connector element 110 to the support element 105. However, it will be appreciated a hooked portion may alternatively be provided as part of the perimeter 105a, configured to receive at least a part of a connector element (for example, a first end or a second end of a connector element having a substantially linear structure) in order to pivotably couple the support element 105 to the connector element. Providing substantially linear connector elements 110 to pivotably couple to sides of triangular support elements 105, for example as described above, may provide a support structure 100 formed from articulated hexagonal structures which are interconnected with one another, as illustrated in Figures 1A to IC and Figure 7A. That may enable the support structure 100 to easily provide a range of different surface topographies which may be able to easily conform to more extreme surfaces having sharper contours, for example as shown in Figure 7C. That may also be conveniently achieved using a simple network of only two repeated identical elements, the triangular support elements 105 and the substantially linear connector elements 110. Each of the triangular support elements 105 may be identical and each of the linear connector elements 110 may be identical whilst still allowing a wide variety of highly contoured surface topographies to be provided. No variants of either the support elements 105 (for example, support elements 105 having a different external shape or perimeter) or the connector elements 110 (for example, connector elements 110 having a different length or configured to pivotably connect to a different number of support elements 105) are required to accommodate more extreme surface topographies, unlike conventional reconfigurable support structures. In particular, such an arrangement may enable more extreme surface topographies to be achieved substantially through pivoting motion of the connector elements 110 alone, without requiring torsion of the connector elements 110 or the support elements 105 to accommodate highly contoured surfaces. In addition, the resulting articulated hexagonal structure provides a number of lines of symmetry about which the support structure 100 may be folded (for example, for storage or transit), as shown in Figures IC and 7B. It will be appreciated generally triangular support elements may be pivotably connected to linear connector elements using any suitable mechanism in order to form a support structure comprising articulated hexagonal structures. For example, the support elements 105 may be pivotably connected to the connector elements 110 using any suitable integral resilient clip mechanism or snap-fit connection, or an alternative releasable connection such as a clamp mechanism (which may be integral to the support structure 100, for example one of the connector elements 110 or the support elements 105 may comprise separable halves between which the other of the connector elements 110 or support elements 105 is disposed), or via a substantially permanent connection. An example of an alternative resilient clip mechanism used in a support structure 300 is shown in Figure 9. In the embodiment shown, a side of a perimeter or outer edge 305a of a support element 305 comprises a recess 305e extending along at least a part of perimeter 305, as shown in cross-section in Figure 9. The recess 305e faces outwards (to the right in Figure 9, with an aperture 305b of the support element 305 located to the left of the perimeter 305a). The recess 305e is configured to receive an end 310a of a connector element 310 in a snap-fit manner substantially as described above, with the recess 305e elastically deforming as an opening of the recess 305e expands to receive the end 310a of the connector element 310. It will also be appreciated a reconfigurable support structure may be formed from support elements having any suitable shape or configuration, for example a substantially circular or polygonal (such as rectangular, pentagonal, hexagonal etc.) shape or perimeter, pivotably coupled to connector elements using any suitable integral resilient clip mechanism or snap fit connection. For example, connector elements 110 may be pivotably coupled to a perimeter of a circular or polygonal support element substantially in the manner described above. Figures 10A and 10B show an example of an alternative support element 405 used in a support structure 400. The support element 405 comprises a substantially pentagonal shape. The support element 405 is pivotably connected to connector elements 410 substantially as described with respect to the support structure 300 shown in Figure 9. Each side of the perimeter 405a comprises a recess 405e configured to receive an end 410a of a connector element 410. Figure 11 shows an example another alternative support element 505 used in a support structure 500. The support element 505 is substantially similar to the support element 405, but comprises a substantially hexagonal shape. The support elements may also not comprise a substantially closed loop structure, but may alternatively comprise a substantially continuous planar structure (for example, may not comprise an aperture bounded by a perimeter of the support element, but may comprise a substantially plate-like structure). Alternatively, each support element may comprise one or more recesses or apertures in or adjacent an outer edge of the support element (for example, in the perimeter 105a of the support element 105), configured to engage with or receive a hooked portion of a connector element 110 as described above. Furthermore, it will also be appreciated the connector elements 110 may be pivotably connected to more than two support elements. For example, each connector element 110 may comprise a substantially Y-shaped or trilobal structure to pivotably connect to three support elements 105, a substantially cross-shaped or four-pronged structure to pivotably connect to four support elements 105, and so on. Each limb or prong of the trilobal, cross-shaped etc. connector element 110 may comprise a hooked portion 110a, although that is not essential. In the embodiment shown, the support elements 105 and the connector elements 110 each comprise complementary engagement features 112 to locate the connector elements 110 on the support elements 105. The complementary engagement features 112 comprise complementary male and female engagement features in the form of a tongue 112a disposed on an internal surface of each hooked portion 110a, and a complementary groove disposed on an external surface of the side of the perimeter 105a of the support element 105. The complementary engagement features 112 are configured to engage with one another without obstructing the pivoting motion of the connector element 110 about the perimeter 105a of the support element 105, for example the complementary engagement features 112 are configured to be in sliding engagement with one another as the connector element 110 pivots about the perimeter 105 of the support element 105. However, it will be appreciated any other suitable engagement features may alternatively be provided. The complementary engagement features 112 may act to both align and locate the connector elements 110 on the support elements 105, and also to provide the support structure with additional strength and rigidity (for example, to resist torsion of the support structure 100). However, that is not essential, and it will be appreciated the support elements 105 and connector elements 110 may be provided without complementary engagement features. In the embodiment shown, the support element 105 also comprises raised portions 105c (shown in Figures 3A and 4B which respectively show a top surface of the support element 105), for example raised relative to the sides of the perimeter 105a generally. In the embodiment shown, the raised portions 105c are each disposed at or adjacent a vertex of the support element 105, although that is not essential. Once the connector elements 110 are connected to the support element 105, the connector elements 110 are substantially prevented or inhibited from moving laterally along the side of the perimeter 105a by the raised portions 105c. A part of the raised portions 105c also extends between adjacent sides of the perimeter 105a which may improve a stiffness of the support element 105. However, it will be appreciated that is not essential, and the support elements 105 may be provided without raised portions. Although not shown, one or both of an internal surface of the hooked portion 110a and an external surface of the perimeter 105a may comprise a textured surface such as a serrated surface, or a surface comprising one or more protrusions such as teeth or pawls (for example, to provide a ratchet surface). The surface(s) may additionally or alternatively comprise a roughened surface. Such surfaces may improve a grip between the connector element 110 and the support element 105 when connected to one another. However, that is not essential. In the embodiment shown, each connector element 110 extends into or is at least partially disposed in the aperture 105b of the support element 105 to which it is connected. The connector elements 110 together define a smaller or secondary aperture or passage 114 within the aperture 105b of the support element, as illustrated in exploded form in Figure 5A. The connector elements 110 pivotably connected to a support element 105 are secured in a desired angular relationship with the support element 105 by a single fastener 120, as shown in Figures 5B, 5C and 5D. In the embodiment shown, the fastener 120 comprises a bolt 120 and a corresponding nut 120a. The bolt 120 passes through the aperture 105b of the support element 105 and through the secondary aperture 114 defined by the plurality of connector elements 110. The presence of the bolt 120 in the secondary aperture 114 prevents the integral resilient clip from being disconnected from the support element 105, by restricting the movement or deformation necessary for the perimeter 105a to exit the opening 110b of the hooked portion 110a. When the bolt 120 is fastened or tightened using the corresponding nut 120a, the bolt 120 and the nut 120a together apply both longitudinal compressive forces (along the longitudinal axis of the bolt 120) and radial compressive forces (in a radial direction from the longitudinal axis of the bolt 120) to secure the connector elements 110 in a desired angular relationship with the support element 105. The radial force exerted by the bolt 120 and the nut 120a when tightened urges the connector elements 110 outward against the sides of the perimeter 105a, securing the connector elements 110 in position relative to the support element 105 and substantially preventing rotation or pivoting of the connector elements 110 about the perimeter 105a of the support element 105. The longitudinal force exerted by the bolt 120 and the nut 120 when tightened acts to close the hooked structure 110a of the connector element 110 around the perimeter 105a of the support element 105a, further securing the components together to preventing rotation of pivoting of the connector element 110. It will also be appreciated the bolt 120 and nut 120a may be used in substantially the same manner to similarly exert longitudinal and radial compressive forces on the perimeter 305a of the support element 305 shown in Figure 9, acting to reduce the effective diameter or width of the recess 305e to secure the support element 305 and the connector element 310 in a desired angular relationship. In the embodiment shown, the bolt 120 is received through the secondary aperture 114 from a bottom side of the support element 105 (the side opposite that on which the raised portions 105c are provided), as shown in Figure 5B. The nut 120a is connected to the threads of the bolt 120 from the opposing top side of the support element 105, as shown in Figure 5C. As shown in Figures 3A and 5A to 5D, each connector element 110 comprises a recessed portion 1 lOd in the form of a notched groove on its outer or external surface. The recessed portion 1 lOd extends along substantially a full length of the connector element 110, between and across both the hooked portions 110a, although that is not essential and the recessed portion 1 lOd may extend along only a part of the outer surface of the connector element 110. When the nut 120a is connected to the bolt 120, the nut 120a is substantially retained within an opening of the secondary aperture such that vertices of the nut 120a are received within or engage with the recessed portions 1 lOd of the connector elements 110, as shown in Figure 5C. That may enable the nut 120a to be secured in position in use without rotating, allowing the bolt 120 to be easily tightened but also retained in position when the bolt 120 is loosened to allow reconfiguration of the support structure 100. The engagement of the nut vertices with the recessed portions 1 lOd may also improve rigidity of the support structure 100, by providing additional resistance to torsional forces. However, it will be appreciated the connector elements 110 may not comprise a recessed portion 1 lOd in their outer surfaces, and the fastener 120 may engage with the general external surface of the connector elements 110. It will also be appreciated than where the support elements and connector elements are connected to one another as shown in Figure 9, the external surfaces of the perimeter 305a may comprise recessed portions configured to engage with the fastener, substantially as described above. As the bolt 120 is tightened is the nut 120a is drawn along the longitudinal axis of the bolt 120 in the direction of the opposing side of the support element 105. Due to the curvature of the hooked portion 110a around the perimeter 105, the secondary aperture 114 narrows towards a central point. As the nut 120a is drawn along the axis of the bolt 120 towards the bolt head, the nut 120a inherently applies increasing radial compressive force to the connector elements 110 as the secondary aperture 114 narrows and the nut 120a engages external surfaces (for example, the recessed portions HOd) of the connector elements 120, urging the connector elements 110 outwards against the perimeter 105a of the support element 105. Similarly, the bolt head can also apply radial compressive force to the connector elements 110 against the curved outer surface of the hooked portion 110a of each connector element 110 as the bolt 120 is tightened. Whilst the above describes the fastener securing three connector elements 110 to a triangular support element 105, it will be appreciated a plurality of connector elements 110 may be connected to a support element 105 having a different configuration (for example, circular, rectangular, pentagonal, hexagonal etc.) in a substantially similar manner. It will also be appreciated that any suitable fasteners 120 may alternatively be used to secure the connector elements 110 and the support elements 105 in a desired angular relationship. For example, an expansion bolt which radially expands on tightening may be used. As another example, a clamp mechanism comprising a shaft passing through the secondary aperture 114 may be used. The clamp mechanism may provide both longitudinal and radial compressive forces as described above. The clamp mechanism may comprise a cam lever to apply and release the compressive forces as require. The shaft of the clamp may be or comprise a polygonal cross-section along at least a part of its length, wherein vertices of the polygonal cross-section may be brought into engagement with the recessed portions 1 lOd of the connector elements 110 as the clamp is tightened. In other alternative arrangements, a respective grub screw disposed in a threaded aperture extending through each connector element 110 or a perimeter of the support element 105 may be used to secure each connector element 110 to the support element 105 in a desired angular relationship. As a further alternative, each connector element 110 may comprise a strap or tie member configured to reduce an effective diameter of the hooked portion(s) 110a when tightened to secure the connector element 110 to the support element 105. The tie member may comprise an elongate strap, for example a cable tie. Further examples of alternative fasteners to secure the connector elements 110 to the support element 105 in a desired angular relationship include a ratchet locking mechanism, a collet or wedge locking mechanism, an eccentric cam mechanism, a concentrically expanding locking mechanism (for example a collapsing cylinder structure) etc. In the embodiment shown, the respective ends of each connector element 110 each comprise a plurality of surfaces IlOe which are angled relative to one another. The angled surfaces IlOe are mirrored about a longitudinal axis of the connector elements 110, although that is not essential. The angled surfaces IlOe of each connector element 110 are angled such that when the connector element 110 is connected to a support element 105, the angled surfaces IlOe of adjacent connector elements 110 are in close proximity to and angled substantially parallel with one another, as illustrated in Figure s 5A. 5B and 5C. That may provide additional strength and rigidity to the support structure 100 when the connector elements 110 are secured in a desired angular relationship with the support element 105, by providing resistance to torsional forces as the angled surfaces IlOe are urged against one another. However, when the fastener 120 is released, the angled surfaces IlOe still slide relative to one another to allow relative pivoting of each connector element 110 independently from the other connector elements 110. Figure 5D shows a plurality of connector elements 110 each at a different rotational position relative to the same support element 105. It will also be appreciated the connector elements 110 may not comprise such angled surfaces at the ends. Figures 6A and 6B show the connection of the support element 105, connector elements 110 and the contact portion 115. Figure 6A shows the arrangement in exploded form, whilst Figure 6B shows the components connected to one another. The connector elements 110 and support element 105 are connected to one another as described above. The contact portion 115 is connected to the support element 105 via an integral resilient clip. In the embodiment shown, the contact portion 115 has a top surface or cover 115e and a surrounding skirt section 115f extending substantially perpendicularly from the top surface 115e. The contact portion 115 comprises a triangular shape substantially similar to the triangular shape of the support element 105, such that the top surface 115e of the contact portion 115 substantially covers the top surface of the support element 105 when the two components are connected. The contact portion 115 comprises a clip 115a located at each corner or vertex of the triangular shape. The clips 115a are configured to be received within corresponding apertures 105d located at each vertex of the support structure. Each clip 115a comprises an elongate structure comprising a retaining portion 115b having a widened crosssection relative to the rest of the clip 115a. Each aperture 105d is formed of two adjacent sections, an upper or shallow aperture section 105d’ having a first width or diameter, and a lower or deep aperture section 105d” having a second width or diameter greater than the first width or diameter (shown in Figures 4A and 4B). The upper and lower sections 105d’, 105d” of the aperture 105d are separated by a shoulder structure where the change in width or diameter takes place. The cross-section of the retaining portion 115b of each clip 115a is wider than a width or diameter of the upper section 105d’ of each aperture 105d. As each clip 115a passes through the upper section 105d’ of an aperture 105d, the narrower width or diameter of the upper section 105d’ causes the retaining portion 115b to elastically deform and reduce in cross-section (either by compressing or by pivoting). As the clip 115a enters the lower section 105d” of the aperture 105d, the stored elastic energy in the retaining portion 115b causes the retaining portion 115b to return to its resting cross-section. The retaining portion 115b engages the shoulder in the aperture 105d, preventing the contact portion 115 from being disconnected from the support element 105 unless sufficient force is applied. However, it will be appreciated any suitable resilient clip mechanism or snap-fit connection may alternatively be used to secure the contact portion 115 to the support element 105, or an alternative releasable connection such as a clamp mechanism, a screw or a bolt, a via a substantially permanent connection. In the embodiment shown, the apertures 105d of the support element 105 are formed in the raised portions 105c located at each vertex of the support element 105. The top surface 115e of the contact portion 115 rests on or is supported by the raised portions 105c when the contact portion 115 is connected to the support element, providing clearance and preventing contact with the connector elements 110. However, that is not essential, and the apertures 105d may be provided in a vertex of the support element 105 that is not raised relative to other parts of the support element 105. The apertures 105d may also be provided or located in any other suitable area of the support element 105d. The apertures 105d may act as a mounting portion to enable additional components including but not limited to the contact portion 115 to be connected to the support element 105. In the embodiment shown, the contact portion 115 comprises a central aperture 115c which is substantially aligned with the aperture 105b of the support element 105 and the secondary aperture 114 formed by the connecting elements 110. That may allow the contact portion 115 to remain connected to the support element 105 whilst enabling a user to access the fastener 120. The support structure 100 may therefore be reconfigured to a different desired surface topography without disconnecting the contact portion 115 from the support element 105. However, that is not essential, and the contact portion 115 may not comprise a central aperture. For example, if connected by a bolt 120 and a corresponding nut 120a, the nut 120a is disposed on the top side of the support element 120, with the bolt 120 passing through the aperture 105b from the opposing bottom side of the support element 120. Once the respective threads of the bolt 120 and the nut 120a are engaged and the nut 120a is located, the bolt 120 may be tightened or loosened by manipulating the bolt head (for example, using a hex ley or a spanner). That way, the support structure 100 may be reconfigured without needing direct access to the fastener 120 from the top side of the support elements 105 on which the contact portions 115 are mounted. Each contact portion 115 comprises a top surface 115e having a substantially smooth outer surface formed from flat and / or curved regions such that the outer surface of each contact portion is substantially free from discontinuities, although that is not essential. The top surface 115e also comprises a resiliently compressible or cushioned surface for a user to contact in use. In the embodiment shown, each contact portion 115 also comprises a plurality of cutaways or recesses 115d. The cutaways 115d are formed in the skirt 115f. The cutaways 115 d may allow rotational movement of the connector elements to reconfigure the support structure 100 to a different desired surface topography, without disconnecting the contact portion 115 from the support element 105. Each of the support element 105, the connector element 110 and the contact portion 115 is formed from a polymeric or plastic material, which may provide a reconfigurable support structure 100 that is strong and rigid yet lightweight (compared to existing reconfigurable support structures which are typically constructed from metallic or metal alloy materials). In the embodiment shown, the connector elements 110 and the support elements 105 are made from or comprise a polyamide such as Nylon-12, although other polymeric materials such as polyacrylate may alternatively be used. In some arrangements, the polymeric material may be or comprise a glass-filled polymeric material which may improve the mechanical properties of the components such as strength and stiffness. The contact portion 115 is made from or comprises a polyurethane (for example, thermoplastic polyurethane, TPU), although other polymeric materials such as thermoplastic elastomers, rubbers, silicone may alternatively be used. The contact portion 115 may also be or comprise a foam material such as a closed-cell foam material to minimise a risk of bacterial growth. The contact portion 115 is made from a biocompatible material, although that is not essential. However, it will be appreciated the support elements 105, the connector elements 110 and the contact portions 115 may be formed from or comprise any suitable material, for example a metallic or metal alloy material, wood etc. The reconfigurable support structure of the present invention may be used to provide support to a body part of a user. For example, the support structure may be used as (or as part of) a seat, a backrest or back support, a neck support or neck brace, a head support. The support structure may be incorporated into a seat such as a wheelchair, a vehicle seat (for example, in a car, van, lorry, motorcycle, plane, boat etc.). The support structure may be mounted on an existing device, such as a wheelchair, seat or a headrest. In one embodiment, the support structure 100 is secured to or mounted on the device using the same fastener (or fasteners) used to secure the connector elements 110 and the support elements 105 in a desired angular relationship. The fastener 120 (for example, a bolt) may extend through the aperture 105a of the support element 105 to engage directly with the existing device, simultaneously mounting the support structure 100 on the existing device and securing the connector elements 110 and support element 105 in a desired angular relationship. However, that is not essential, and the support structure may be mounted in any suitable manner, for exampling using any suitable connection means. Figures 8A and 8B show another embodiment of a reconfigurable support structure 200 for providing a desired surface topography. Figure 8A shows the components of the support structure 200 in exploded form, whilst Figure 8B shows the components connected to one another. The support structure 200 is substantially similar to the support structure 100 described with respect to Figures 1 to 7, with like reference numerals indicating like elements. The support structure comprises one or more force and / or pressure sensors 220. That may enable a user to determine a distribution of force and / or pressure across the support structure 200 in use, for example to assess if the support structure is correctly confirmed or fitted to a body surface of the user. The sensors 220 are mounted between the top surface of the support element 205 and the underside of the contact portion 215, such that the sensor 220 is secured in place between those two components once they are connected. In the embodiment shown, the sensors 220 are sandwiched between an outer surface of the connector elements 210 and the underside of the contact portion 215. The sensor 220 may alternatively be mounted or connected directly to one of the support element 205, the connector element(s) 210 and the contact portion 215. When a force is applied to the contact portion 215, the sensor 220 is compressed between the contact portion 215 and the connector element 210 or support element 205, allowing a force and / or pressure measurement to be made. Locating the sensor 220 beneath the contact portion 215 may also protect the sensor 220 from mechanical damage (for example, due to impact) during use. In the embodiment shown, the sensor 220 is located to substantially align with the central aperture 215c of the contact portion 215. The sensor 220 may alternatively be located at any suitable position on the support structure 200, for example adjacent a corner or vertex of the contact portion 115 or the support element 105. From reading the present disclosure, other variations and modifications will be apparent to the skilled person. Such variations and modifications may involve equivalent and other features which are already known in the art of support structures, in particular reconfigurable support structures, and which may be used instead of, or in addition to, features already described herein. Although the appended claims are directed to particular combinations of features, it should be understood that the scope of the disclosure of the present invention also includes any novel feature or any novel combination of features disclosed herein either explicitly or implicitly or any generalisation thereof, whether or not it relates to the same invention as presently claimed in any claim and whether or not it mitigates any or all of the same technical problems as does the present invention. Features which are described in the context of separate embodiments may also be provided in combination in a single embodiment. Conversely, various features which are, for brevity, described in the context of a single embodiment, may also be provided separately or in any suitable sub-combination. The applicant hereby gives notice that new claims may be formulated to such features and / or combinations of such features during the prosecution of the present application or of any further application derived therefrom. For the sake of completeness, it is also stated that the term “comprising” does not exclude other elements or steps, the term “a” or “an” does not exclude a plurality, and any reference signs in the claims shall not be construed as limiting the scope of the claims.

Claims

1. A reconfigurable support structure for providing a desired surface topography, the support structure comprising:a plurality of support elements;a plurality of connector elements, wherein each connector element is pivotably connected to at least two support elements;wherein the connector elements and support elements are connected to one another via an integral resilient clip; anda plurality of fasteners arranged to releasably secure the connector elements and support elements in a desired angular relationship.

2. The support structure of claim 1, wherein:a) each connector element comprises a resilient clip configured to receive a part of a support element; orb) each support element comprises a resilient clip configured to receive a part of a connector element.

3. The support structure of claim 1 or of claim 2, wherein each fastener is arranged to engage multiple connector elements to releasably secure the connector elements and support elements in a desired angular relationship.

4. The support structure of any preceding claim, wherein each support element comprises a substantially closed loop structure forming a perimeter surrounding an aperture of the support element.

5. The support structure of claim 4, wherein each connector element is pivotably connected to the respective perimeters of the at least two support elements.

6. The support structure of claim 5, wherein each connector element is configured to pivot about the respective perimeters of the at least two support elements.

7. The support structure of any of claims 4 to 6, wherein each fastener is at least partially located in an aperture of one of the support elements to releasably secure the connector elements and support elements in a desired angular relationship.

8. The support structure of claim 7. wherein each connector element extends into the respective aperture of the support elements to which it is connected.

9. The support structure of any of claims 4 to 8, wherein a fastener is received through the respective aperture of a support element to secure a plurality of connector elements to that support element.

10. The support structure of claim 9, wherein the fastener is arranged to engage with the support element or with each connector element connected to the support element, and optionally wherein the fastener is arranged to engage an external surface of the support element or an external surface of each connector element connected to the support element, and further optionally wherein the support element or each connector element comprises a recessed portion on its external surface configured to receive at least a part of the fastener when the fastener engages the support element or each connector element, and further optionally wherein the recessed portion comprises a notched groove.

11. The support structure of any of claims 7 to 10, wherein the fasteners are configured to exert a force in the plane of the support element to secure the connector elements and support elements in a desired angular relationship.

12. The support structure of any preceding claim, wherein each fastener comprises one of a bolt and nut, a clamp mechanism, a grub screw or a set screw, a strap or tie member, a ratchet locking mechanism, a collet or wedge locking mechanism, an eccentric cam mechanism and an expanding locking mechanism ,13. The support structure of any preceding claim, wherein each connector element comprises a substantially linear structure comprising a first end and a second end.

14. The support structure of any preceding claim, wherein each connector element is pivotably connected to each of the at least two support elements via a hooked portion of the connector element.

15. The support structure of any preceding claim, wherein the plurality of support elements and plurality of connector elements each comprise complementary engagement features to locate the connector elements on the support elements when connected to one another, and optionally wherein the complementary engagements features comprise a tongue and a groove.

16. The support structure of any preceding claim, wherein each of the plurality of support elements are substantially identical to one another, and each of the plurality of connector elements are substantially identical to one another.

17. The support structure of any preceding claim, wherein each support element comprises a mounting portion configured to enable additional components to be secured to the support element, and optionally wherein the mounting portion is located at a vertex of the support element.

18. The support structure of any preceding claim, further comprising one or more contact portions mounted on one or more of the support elements.

19. The support structure of any preceding claim, further comprising one or more force and / or pressure sensors, and optionally wherein the one or more force and / or pressure sensors are mounted on one or more of the support elements.

20. The support structure of any preceding claim, wherein each support element comprises a polygonal structure.

21. The support structure of claim 20, wherein each support element comprises a triangular structure.

22. The support structure of claim 21, wherein the plurality of triangular support elements are connected via the connector elements to form a plurality of articulated hexagonal structures.

23. The support structure of claim 22, wherein each articulated hexagonal structure consists of six triangular support elements, and wherein each triangular support element in the articulated hexagonal structure is connected to each of the two neighbouringtriangular support elements in the articulated hexagonal structure via a respective connector element.

24. A support for a body part comprising the reconfigurable support structure of any 5 preceding claim.

25. A wheelchair comprising:the reconfigurable support structure of any of claims 1 to 23; orthe support of claim 24.

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