Patent Application
20210113413
The present invention generally relates to a rehabilitation apparatus for aiding in learning or relearning to walk, particularly following a person having suffered a stroke or other traumatic loss of movement in the lower limbs.
There are a number of causes for a loss of function or control of lower limbs, which can include serious brain events, injury, and illness. Where an individual suffers such a loss, this can severely impair their ability to walk. Relearning to walk is often a lengthy process requiring the aid of physiotherapists and other health professionals. Tools for aiding this relearning are becoming increasingly dated, and space consuming.
Current rehabilitation methods for relearning how to walk include a set of, rudimentary, parallel bars. These bars are set to the appropriate height for the user, who then supports himself in order to move their legs. This method, although simple, has been shown to aid in relearning. The method however, proves a problem for an individual where they reach the end of the bars, and have to turn 180 degrees to continue using the bars to support himself. Turning himself can prove an energy consuming task, which detracts from the narrower focus of relearning each stage of the leg movement in the walking process.
This project addresses the need for a cost-effective, user-friendly device to meet a priority rehabilitation need: the ability to walk independently after stroke. This innovation is expected to also meet the requirements of other patient groups. Existing devices for retraining walking: have limited evidence of benefit, are expensive, are difficult to use in rehabilitation settings particularly in peoples' homes, and/or are poorly designed. Current clinical practice, i.e. 2-3 therapists supporting legs/arms/trunk of the stroke survivor, cannot provide sufficient repetitive practice of the normal walking needed to drive brain recovery. Electromechanical walking training is recommended in national stroke guidelines but our market research indicates lack of a device: for practice of normal walking patterns; usable in rehabilitation settings; and commercially viable to manufacture and market.
Further current rehabilitation methods consist of the use of treadmills. The general nature of a treadmill provides a system having a moving belt which does not provide any guidance for appropriate placement of the foot, unless a therapist is present who actually lifts the foot for the patient-typically supported by a body harness—as the foot travels along the planar surface of the foot-engaging portion. This planar motion of foot travel does not rehabilitate a user to lift and plant their foot as they would when walking normally, rather this method produces a foot sliding action. Moreover, on a typical treadmill there is a serious risk of the user tripping.
It is to these problems amongst others, that the invention attempts to offer a solution.
According to a first aspect of the invention, there is provided an apparatus to aid walking, the apparatus comprising a base unit, housing a motor; and further comprising first and second horizontally orientated foot supports, mounted for back and forth parallel motion relative to the base unit;
the foot supports each being operably connected to the motor;
a foot support comprising a plurality of planar members, including a base plate, an intermediate plate and a foot plate having an upper surface to receive a user's foot, the intermediate plate being pivotally linked at a first end to the base plate and at a second end to the foot plate.
Optionally, the foot plate includes a retention means to retain the foot against an upper surface of the foot plate. Further optionally, the foot plate includes a heel support to provide stability to a user's foot.
Preferably, the foot supports are housed for motion within channels within the base unit and further preferably, the upper surfaces of the foot plates are below or level with the upper surface of the base unit to enable a user to step down onto or simply across from the base unit onto the foot supports.
Conveniently, the foot supports are independently moveable back and forth. Alternatively, the movement of the foot supports is linked by means of a coupling, forward motion of one of the foot supports causing rearward motion of the other foot support.
Preferably, back and forth motion of the foot supports is governed by a processor to enable a specified programme of movements to be undertaken by a user, which processor is further preferably an Arduino processor.
Advantageously, the apparatus includes a stop button, operation of which, disconnects power to the foot supports, which allows a support worker to aid a user more easily in the event of problems occurring.
Optionally, the apparatus comprises two independently operable motors, the first motor driving the first foot support and the second motor the second foot support.
Preferably, one or more supports extend upwardly from the base unit to act as hand support for a user or to provide a suitably elevated location point for other forms of support for the upper body, which varies according to different patients' needs. Further preferably, the height of the support on top of the base is adjustable. Yet further preferably, a support comprises two upright support elements extending from the base, one rearward of the base unit and one forward of the base unit, and connected by a cross-piece. Still yet further preferably, the vertical supports are pivotally mounted to the base unit, enabling the tubular supports to be pivoted to lie against the base unit for storage or transport. More preferably, the apparatus comprises two supports to either side of a user to aid a user in retaining upright whilst using the apparatus.
Preferably, a motor is connected to the foot supports by one or more drive belts, said belt being selected from a toothed belt, chain belt or the like.
Optionally, the intermediate plate is linked by means of a hinge to the base plate to allow the front end of the intermediate plate to pivot away from the base plate.
Further optionally, the foot plate is linked by means of a hinge to the front end of the intermediate plate. Yet further optionally, the intermediate plate is linked to the foot plate between the front and the back of the foot plate, and still further optionally to the front half of the foot plate.
The invention will now be described with reference to the figures, of which:
The top platform 2 comprises a raised forward portion 4 and a user-engaging flat portion 5. The flat portion 5 comprises a right runway 16 and a left runway 17. The runways 16, 17 are elongate apertures in which footplates 6, 7 are slidably housed such that the footplates 6, 7 can move in a back and forth motion along the respective runway 16, 17. The footplates 6, 7 are also housed such that their upper surfaces are at the same height, where the top surface, or foot-receiving portion 49, is level with the surface of the top platform 2. This aids a user in stepping on and off the footplates. The height of a footplate 6, 7 is optionally adjustable to take the account of any variations in effective length of a user's leg. In an alternative optional embodiment, not illustrated, the patient's leg length can be taken into account by altering the stroke of the platform's reciprocating motion. The footplates' 6, 7 movement is driven by a motor located within the body of the device 1.
Although the footplates 6, 7 can be housed in the runways 16, 17, the footplates 6, 7 do not have to be in contact fit with the vertical walls of the runways 16, 17. This allows an individual footplate 6, 7 to rotate about an approximately vertical axis of the footplate 6, 7 centre point. By allowing this rotation, the footplate 6, 7 can be rotated to enable use by those users whose feet point inwards or outwards during walking. The rotation also allows a user who may swing their leg outward in order to take a step, to maintain their foot within the footplate 6, 7 itself. The footplate 6, 7, can however, be fitted with a compliant or fixed-stop limiter, in order to reduce the rotational movement. This enables a user's movement to be limited or controlled, where the user displays an excessive foot or leg motion which needs to be corrected.
Extending from the flat portion 5 are four hinge mountings: two left hinge mountings 18 located toward the outer edge of the flat portion 5, and two right hinge mountings 19 located to the edge of the parallel edge portion. Each pair of hinge mountings 18 and 19, hingeably engages in-use lower end 18a, b, 19a, b of a left 9 and right 8 support. Each support extends, in use, upwardly perpendicular to the surface of the flat portion 5. Each support 8 and 9 is constructed of two uprights and a connecting rail 24. The uprights comprise a lower support portion 22 and an upper support portion 23. The lower support portion 22 includes a support adjust pin 14. The support adjust pin 14 extends through an aperture on each side of the lower support portion 22, to lock the upper support portion 23 at a desired height. The upper support portion comprises a series of apertures 21 for receiving the support pin 14 in use. The particular aperture 21 allows the connecting rail 24 to be brought to a height to suit the user. The connecting rail 24 of the support 8 and 9, comprises a handle 15a and 15b that a user can hold onto. Each handle 15a and 15b comprises a series of apertures 20, to which attachments can be secured, as detailed in later embodiments.
Each support 8, 9 comprises an emergency stop button 13a and 13b. A further emergency stop button 12 is located on the raised forward portion 4. The emergency stop buttons 13a and 13b on the supports 8, 9 are located to provide ease of access for a user or their aide to deactivate the device 1 motors immediately. The height at which the emergency stop buttons 13a and 13b are arranged also allows ease of access for a supporting health professional to stop the motors. The emergency stop button 12 of the forward portion 4 of the top platform 2 is located for ease of interaction by a foot. A supporting health professional can deactivate the device 1 motors by foot interaction with the emergency stop button 12 whilst maintaining interaction with the user. In a further embodiment, not illustrated, if power beyond a pre-set value is drawn, this can be taken as an indication that the machine is jammed, possibly by something being caught in the drive mechanism, and the power cut. In a yet further non-illustrated embodiment, an automatic kill switch style emergency stop is accommodated. Such a device consists, for example, of a fixed cord attached to the user on one end, and the device on the other end. If the patient or supervisor pulls or yanks the cord, or the user falls or moves outside the radius of the designed cord length, the switch automatically stops the machine safely
The top platform 2 comprises handle apertures 10a and 10b, and 11a and 11b. The ground engaging base 3 comprises recesses 25a and 25b, and 26a and 26b that mirror the location and shape of the handle apertures 10 and 11, allowing a user or users to carry and/or manoeuvre the device 1. Ground-engaging wheels, which can be lockable against rotation, can be provided to aid in the movement of the device 1 between locations.
The left and right runways 17 and 16 are located in the flat portion 5 of the top platform 2, situated parallel to one another. Each runway 17 and 16 comprises a footplate 7 and 6 which, in use, travels back and forth along the length of the runways 17 and 16 respectively, to aid in simulating the walking process.
The user's foot is maintained in position on the footplate 40 by the heel support 48, and strap 47 which maintains the forward portion of a user's foot against the foot receiving portion 49. This arrangement allows the foot to flex around the big toe joint. The foot receiving portion 49 is formed of a flexible material, for example a soft plastic, or thick rubber that allows the foot receiving portion 49 to flex with the user's foot in use. By providing a flexible material for the foot receiving portion 49, the heel support 48 can move with the user's heel, and remain in contact throughout the multiple positions that result through a range of walking gait motions.
Pivoting about the top plate hinge 46 is assisted at this part of the stride by pressure from the front of the user's foot on the portion of the top plate 45 forward of the top plate hinge 46, the force about the top plate hinge 46 thereby provided acting about the top plate hinge 46 in the same rotational manner as that produced by lifting the heel support 48. As the user draws up on the footplate 40, the base 41 slides forward in its respective runway. This sliding motion replicates the act of striding in walking. As the footplate 40 travels forward in a prescribed and controlled motion on its runway, the second footplate, attached to a user's second leg, slides rearward, also in a controlled motion. This replicates the action of a striding leg passing a stationary leg in walking.
Each runway comprises a recess wherein the centre portion comprises an aperture, into which a toothed belt is positioned. The walls of the recess are constructed so as to comprise a low friction guiding surface that is in contact with the sides of a footplate. This allows the footplate to slide against these surface, in use. The base of the footplate has wheel or race bearing carriages or similar means to allow the footplates to have low rolling resistance
Each individual footplate 40 is attached to a toothed belt, chain or other suitable means within the runway recess. For example, linear actuation means such as pneumatic, hydraulic, electrical, ball and lead screw, chain, rack and pinion or cable mechanisms can be used. The toothed belt means is connected to a pulse width modulation (PWM) servo motor. Other methods of linear speed control to vary speed can be used (e.g. in the case of AC servos, frequency control), in the case of a CVT (constantly variable transmission) gearbox, dynamic change of gearbox ratio, can be used. The motor is variable speed, and can be controlled by either the user, an operator or a microcontroller such as an Arduino microcontroller, and piggyback 10A ‘buffer’ shield. As an alternative a stepper motor can be used. Each runway, or carriage, is independent from the other. The mode of operation of the runway and footplate 40 function is to synthesize characteristic human foot positions throughout a range of walking gait motions. The device can be controlled by an operator to ensure that the speed of the footplates along their respective runways is adequate to allow a user to carry out their exercises. The operator can control the speed of the footplate movement within the runways manually, by way of software controlling the device. From the software, the operator can monitor all aspects of speed, and weight distribution between a user's feet. Moreover, the software can be utilised to replicate the front to back motion of a typical stride cycle, controlling aspects such as, and referring to
This motion can be derived by reverse engineering via measured gait analyses from patients and healthy subjects. Alternatively, the motion can be synthesized and ‘profiled’ where this could provide therapeutic benefit. For example, asymmetrical left/right movement, exaggeration or reduction of the acceleration profile, progressive change of stride length during therapy, for example.
First, the foot of the user is attached to the top part of the Z-plate (which is a flexible element in this embodiment) so that the foot can be lifted (comparatively) easily off the ‘ground’.
This allows the foot to be raised under the user's own effort during the swing (return) phase of the walk. To achieve this important transition, the user must perform a weight shift onto their opposite leg. This is a neurologically significant element of walk and larger prior art, robotic devices ‘force’ this motion in a less natural fashion. Conversely, treadmill walking, known in the prior art, allows the free passage of the foot during the swing phase, though this is unsafe (trip hazard) and does not instil the acceleration/deceleration movement that the patient is trying to re-learn.
The gait width is constrained. This is fixed by the device, though in some embodiments, the width can be adjusted to suit varying patient needs as a production solution. In addition, adjustment can be made, and means provided to accommodate toe-in and toe-out conditions. This is only limited mechanically by potential interference between the left and right ‘plates’, though there may be angle limits imposed by user benefit; for example, if the foot was misaligned too far from straight ahead, this could create unfavourable joint loading. This would need to be determined by clinical evaluation.
The footplate used on the device is similar to those known in rowing machines found in a gym. However, effective means to hold the foot in position is important. This method may vary depending on different patient conditions. However, selective compliance (rather than a rigid Z-plate) can make the device more comfortable.
The footplate needs to accommodate a range of foot sizes as a user may or may not be wearing footwear. The heel should be maintained proximate to the rear hinge, such that during heel strike, there is good correlation between the user's heel and the point at which it strikes the ground.
During ‘toe off’, the foot flex is used to provide momentum to allow the weight shift to the opposite leg (described above). Where a user has difficulty initiating this lift (at the end of the pre-swing), a ‘cam’ or powered heel ‘pusher’ can be provided to assist. As a basic form of heel lift device, a switch can be incorporated that halts the walk cycle unless the user lifts the heel at the right moment. However, such a switch can be disruptive to normal walking. The lowest element of the Z-plate is, in effect, the floor ‘datum’.
In a further embodiment, the top plate hinge 46 is located at the foot-receiving portion 49 end of the central plate 44. In this embodiment, the foot-receiving portion 49 is flexible along its entirety and joins directly to the top plate hinge 46. This embodiment allows the user to pivot about the toe, further replicating the natural gait by allowing the user to extract the foot from the heel through to the toes. The toes, in use, are positioned about the toe-receiving end 51 of the foot-receiving portion 49. This ensures that the foot-receiving portion 49 moves with the user's foot, and therefore ensures that no excess of the toe-receiving end 51 is present.
To accommodate for users with smaller feet, the heel support 48 can be adjusted to position the user's foot correctly on the foot-receiving portion 49. There are a number of options for adjustment means. These include, a toe region adjustment means that the user adjusts by slotting retaining plugs into receiving apertures. Alternatively, the heel support 48 can be moved respective of the foot-receiving portion 49 by a strap adjustment means, this allows the user to position the heel support 48 so as to ensure that their feet engage the respective foot engaging portions correctly.
The further advantage of the footplate 40 design, which features hinged portions, allows the user to move their ankle. The ankle and feet, comprise proprioceptors, which provide the body's ability to sense movement within joints, and also determine joint positioning. By developing proprioceptors, an individual does not have to look at, for example, their foot in order to determine its positioning. The hinged footplate 40 enables the user to move their feet and ankle in a manner that is less restricted, and therefore develop their proprioception.
The second attachment is a hoist 33. The hoist 33 comprises left and right support base-frame extensions 34a and 34b. Each extension 34 comprises a wheel 35a or 35b at its end portion. Each wheel 35a and 35b is manoeuvrable about a 360-degree rotation through its attachment to the respective extension 34. Each extension extends from a hoist frame centre unit 67. The extensions 34 are so spaced as to allow the hoist to be positioned about the apparatus 1, where the apparatus 1 is located between the extensions 34. The centre unit 67 comprises two wheels 35c and 35d, each manoeuvrable about 360 degrees.
A support frame 36 extends upwards from the centre unit 67 to from a curved ‘c’ profile that extends, in use, over the top of the apparatus 1. A reinforcement piston 37 extends between a lower portion and upper portion of the support frame 36, so as to provide support where flexion in the frame 36 occurs whilst supporting the weight of a user. Alternatively, in place of the reinforcement piston, a linear actuator or locking gas strut can be used to provide the support. The frame comprises a harness attachment means 38 for attaching a user's harness, to support the weight of the user in use. The frame 36 further comprises a manoeuvring handle 39, the handle 39 including controls 60 and emergency stop button 61 for a healthcare worker aiding the user to operate the apparatus for the user. The hoist controls 60 allow for the healthcare worker to raise and lower the user where necessary. The controls in connection with the apparatus are actuated either via an external network through wireless means, or via direct contact through a wire. The centre unit 67 comprises an apparatus-engaging protrusion 62. This protrusion 62 fits into a receiving aperture or recess on the first end of the apparatus 1. This fit, maintains the hoist 33 in its in-use position, by preventing sidewards movement of the hoist 33 relative to the apparatus 1. The hoist 33 can also comprise brakes on an individual or each wheel 35 to prevent shifting of the hoist 33 in use.
The third attachment is a knee rest 63. The knee rest 63 comprises a knee-engaging portion 64, connected to a knee rest support frame 65 comprising a top portion-engaging means 66 at its lowest portion. The knee rest 63 in use acts to support the front of a user's knees, or top of their shins. The knee rest is used to lock the user's lower limbs in position whilst they the hoist is used to lift them into a standing position. A carry handle 50 is located at the top of the knee rest frame 65 so as to allow the knee rest to be removed and installed quickly.
The apparatus 1 can be powered by a number of suitable means. Preferably the apparatus comprises a power cable which can be plugged into a mains electricity source. The power cable extends preferably from the first end of the apparatus 1 so as to reduce the likelihood of the user tripping when mounting the apparatus 1 from the second end. Alternatively, the apparatus can be powered by a suitable battery or other power source known in the art. The battery can, for example, be charged in line when using the apparatus powered from a mains supply. The use of a battery power source enables the apparatus 1 to be more mobile and therefore taken into an area where the power supply is limited.
The apparatus 1 can be provided in varying sizes. The apparatus 1 can be sized to accommodate individuals of different frame sizes, and to accommodate smaller spaces for use, should the user have reduced surface area into which the device can be set up.
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| Number | Date | Country | Kind |
|---|---|---|---|
| 1804717.5 | Mar 2018 | GB | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/GB2019/050817 | 3/22/2019 | WO | 00 |
