SE541686C2

SE541686C2 - Device for stabilizing movement of a limb

Info

Publication number: SE541686C2
Application number: SE1751359A
Authority: SE
Inventors: Björn Nilsson
Original assignee: Bjoern Nilsson Utveckling Ab
Priority date: 2017-11-02
Filing date: 2017-11-02
Publication date: 2019-11-26
Also published as: SE1751359A1; WO2019088903A1

Abstract

Device and method for stabilizing the movement of a limb comprising a body part supporting device (15) connected to a counterweight means (11) and a foot-operated auxiliary force provider (23) such as a pedal (41; 51) or a carriage (31) for assisting in raising or lowering the limb.

Description

Device for stabilizing movement of a limb Field of the invention The present invention relates to devices for assisting a patient in controlling the movement of an upper limb of the patient which limb suffers from uncontrolled shaking and/or tremors and/or spasms and/or weakness and/or reduced motor control or the like. A patient who has an arm which is subject to one or more of these problems may have problems feeding himself or herself. Spasms or shaking of the arm may mean that the feeding utensil misses the mouth or tilts, hereby dropping the food. Weakness in the arm may make feeding tiring and frustrating. Devices are needed to reduce the effect of involuntary movements and weakness in order for the patient to become more selfsufficient.

Background of the invention Devices are known for supporting the weight of arm or wrist by means of a counterweight, for example from AU2004202312. This uses a system of pulleys and counterweights to support an arm which is intended to be held in a substantially static position for long lengths of time.

Another device known from US20160287427 uses springs and a cam to compensate for the weight of an arm when the arm is raised or lowered during rehabilitation exercises.

A problem with such prior art devices it that that they merely compensate for the effects of gravity, thereby making it easier to raise the arm, but they do not prevent or reduce the problems caused by badly-controlled or uncontrolled shaking, tremors or spasms when the afflicted patient is trying to feed himself or herself.

Summary of the invention The object of the present invention is to provide a device which reduces or eliminates the problems caused by the uncontrolled or badly-controlled movements of the patient's limb or problems caused by weakness in the limb.

This is achieved by the device for stabilizing movement of a limb defined in claim 1 and the method as defined in claim 16.

The device for stabilizing movement of a limb according to the invention comprises: a) a frame comprising a substantially upright tube connected at a first end to a base and at a second end to a substantially horizontally-projecting transverse arm; b) a counterweight mean slidably mounted in or on theupright tube; c) a body part supporting device; d) flexible connection means for connecting said counterweight means to said body part supporting device; The body part supporting device is suspendable from the transverse arm by the flexible connection means. The flexible connection means and/or the counterweight means is/are connected to a footoperable auxiliary force provider arranged for adjusting the position of said counterweight.

The foot-operable auxiliary force provider may for example be a carriage movable towards and away from said upright tube; a pedal movable towards and away from said upright tube; or a roller rotatable about an axis. The pedal may be pivoted about a top pivot, a bottom pivot or an intermediate pivot.

The counterweight means may be provided inside the upright tube. The upright tube may be provided with damping means for damping the movement of said counterweight means.

Brief description of the drawings Figure la) shows schematically a lateral view of an example of a device in accordance with the present invention when an arm is in a lower position and figure lb) shows the device when the arm is in a raised position.

Figure 2a) shows schematically a lateral view of a second example of a device in accordance with the present invention when an arm is in a lower position and figure 2b) shows the device when the arm is in a raised position.

Figure 3a) shows schematically a lateral view of a third example of a device in accordance with the present invention when an arm is in a lower position and figure 3b) shows the device when the arm is in a raised position.

Figure 4a) shows schematically a lateral view of a fourth example of a device in accordance with the present invention when an arm is in a lower position and figure 4b) shows the device when the arm is in a raised position.

Detailed description The present invention relates to a device for compensating for some or all of the weight of a limb, for example an arm, of a patient while the limb is being moved. The device will be described in detail by means of the following, non-limiting illustrative examples of the invention in which parts which are similar in the different examples have been given the same reference number.

Figures 1a) and 1b) show a first example of a device 1 in accordance of the present invention. The device has an inverted L-shaped frame 3 comprising a hollow, upwardly- projecting, upright tube 5 with a preferably hollow, horizontally-projecting transverse arm 7 attached, on or near, the top 9 of the upright tube 5. The upright tube 5 is preferably vertically-projecting. However it may be inclined from the vertical, up preferably within an angle equal to or less than 15 degrees from the vertical. Thehorizontally-projecting transverse arm preferably projects horizontally or the further end is at an angle equal to or less than 15 degrees above or below the horizontal from the end attached to the upright tube 5.

The device is fitted with a base foot or stand (not shown) or is mounted to a floor or wall or the like or a piece of furniture in order to prevent it from moving or tipping during use.

Upright tube 5 is preferably hollow to allow a counterweight and other moving components described below to be safely contained within it. The upright tube 5 is preferably vertically projecting so that the weight of the counterweight means 11 inside it (described below) is not partly taken by the interior surface 13 of the upright tube as this would reduce the counterweighting effect of the counterweight. A body part supporting device 15 such as a sling (or other device such as a cuff or glove or arm rest) into which the patient can insert or rest a body part 17 such as a hand or wrist or lower arm so that the body part is supported by the body part supporting device 15 is suspended from, or near, the outer end 19 of the transverse arm 7, i.e. the end of the transverse arm 7 which is not attached to the upright tube 5. The body part supporting device 15 may be weighted to give it more inertia which will reduce the effect of involuntary tremors on the movement of the body part supporting device 15. The weight of the body part supporting device 15 can be, for example, preferably equal to or greater than 200 grams and equal to or less than 1.5 kilograms, more preferably equal to or greater than 300 grams and equal to or less than 1.2 kilograms and most preferably equal to or greater than 400 grams and equal to or less than 900 grams. The force needed to lift such extra weight, can be compensated for by increasing the mass of the counterweight means 11. Transverse arm 7 projects substantially horizontally to provide clearance between the body part supporting device 15 and the upright tube 5. The transverse arm 7 is preferably rotatable about the central axis of the upright tube 5 in order to allow the position of the sling to be adjusted through a horizontal arc. The sling is connected by a wire or other flexible connection means 21 for example a chain or rope or line or the like or combinations thereof, to the counterweight means 11.

Counterweight means 11 is preferably positioned inside the tube to reduce the need to clean it and to avoid the risk of objects being caught between the counterweight means 11 and the upright tube 5, when it moves up and down in relation to the upright tube 5. The counterweight means 11 is preferably able to be adapted to the weight of the patient's body part and the body part supporting device 15 so that it takes little effort to move the body part up or down. This can be achieved, for example, by adding or removing solid or liquid material from the counterweight means 11 as described in more detail below. Counterweight means 11 can be in many different forms. In the simplest form it comprises one or more preferably cylindrical weights which can be suspended individually or in sets from the wire inside the tube in order to provide the necessary counterweighting force. A different counterweight means 11 could comprise a container which can be suspended from the wire, which container could be filled with the amount of some material, for example lead shot, sand, steel or glass balls, or the like, water, other liquids or combinations thereof, necessary to give the required counterweight load. The counterweight means 11 adds inertia to the system comprising the counterweight means 11, wire, the body part supporting device 15 and patient's arm, which increased inertia is thought to help keep the patient's arm in balance.

Furthermore the counterweight means 11 reduces the force which the patient needs to exert to lift the arm against the force of gravity as the counterweight means 11 provides a lifting force f1 to the body part supporting device 15. The counterweight means 11 preferably fits with a sliding fit inside the upright tube 5 which means that its movement is damped by the air that it needs to displace when moving up and down. The upright tube 5 is preferably closed at the upper end and can be provided with adjustable damping means in the form of one or more openings 25 which extend from the interior of the tube to the exterior of the tube and which allow air to enter or leave the tube as the counterweight means 11 moves up and down the tube. Opening size regulating means 27 such as a movable cover which can restrict the cross-sectional area of the opening can be used to change the amount of air damping. Air damping is thought to add stability to the movements.

The device is provided with a foot-operated auxiliary force provider 23 which allows the patient to use a foot 29 to assist the vertical movement of the sling. This adds force to the movements.

In the embodiment of the invention shown in figures 1a) and 1 b) foot-operated auxiliary force provider 23 is in the form of a carriage 31 connected by a wire or the like 32 around pulley wheels 33, 37 to the counterweight means 11 and body part supporting device 15. As shown in figures 1a) and 1b), the carriage 31 can be pushed away for the patient by placing a foot on the carriage 31 and then moving the foot and carriage 31 forwards and/or transversely in order to raise the body part supporting device 15. The wire 32 passes around the two pulley wheels 33 and 37 which act to double the movement and halves the force f2 provided by the displacement of the carriage 31 so that moving the carriage 10 cm causes the counterweight means 11 to move 20 cm. Moving the carriage 31 back towards the patient will cause the body part supporting device 15 to be lowered. It is also conceivable to add additional pulleys and/or levers or the like so that the movements work in the reverse sense, i.e. pushing the carriage 31 towards the patient raises the body part supporting device 15 and vice versa. Further pulley wheels or levers or the like, or a series of pulleys and/or levers or the like, can be arranged in the system to adjust the gear ratio between movement of the patient's foot and movement of the patient's arm.

The embodiment of the invention shown in figures 2a) and 2b) is substantially the same as that of figures la) to lb) except that the foot-operated auxiliary force provider 23 is in the form of a topmounted pedal 41 pivotable about a top-pivot 45 at the top of the pedal and connected by the wire 42 and pulley wheels 43, 47 to the counterweight means and body part supporting means. The pedal 41 can be pushed forward by the patient to raise the body part supporting device 15 and allowed to moved backwards to lower it. It is also conceivable to add additional pulleys and/or levers or the like so that pushing the pedal forward lowers the body part supporting device and vice versa. One pulley 47 or lever or the like, or a series of pulleys and/or levers or the like, can be arranged in the system to adjust the gear ratio between movement of the patient's foot and movement of the patient's arm.

In the embodiment of the invention shown in figures 3a) and 3b), the foot-operated auxiliary force provider 23 shown in figures la) to lb) is replaced by an auxiliary force provider in the form of a base-mounted pedal 51 pivotable about a bottom pivot 55 at the base of the pedal 51 and connected by the wire 52 and pulley wheels 53 to the counterweight means 11 and body part supporting device 15. The pedal 51 can be pushed forward by the patient to raise the body part supporting device 15 and allowed to moved backwards to lower it. It is also conceivable to add additional pulleys and/or levers or the like so that pushing the pedal forward lowers the body part supporting device 15 and vice versa. One pulley 57 or lever or the like, or a series of pulleys and/or levers or the like, can be arranged in the system to adjust the gear ratio between movement of the patient's foot and movement of the patient's arm.

It is of course conceivable that the foot pedal 41; 51 is rotatable about other forms of pivot, for example an intermediate pivot, the axis of which is in an intermediate position between the ends of the pedal 41; 51.

Figures 4a) and 4b) show a further embodiment of the present invention in which the foot-operated auxiliary force provider 23 shown in figures la) to lb) is replaced by an auxiliary force provider in the form of a roller 61 mounted on a frame 65 which preferably rests on the floor. As shown by solid lines the roller 61 can be mounted with its longitudinal axis A substantially horizontal and can be arranged to be rotatable about this axis in the frame. Alternatively it can be mounted with its longitudinal axis 66 vertical as shown by dashed lines or inclined at an angle a to the vertical as shown by dotted lines in figure 4a). The roller 61 is provided with a pulley wheel 63 around which a wire 62 or the like, which is connectable to the counterweight means 11, can be wound or unwound by rotation of the roller 61. The roller 61 is preferably sufficiently long so that the patient can rest both feet on it. One foot can act as a friction brake to prevent rotation of the roller 61 while the sole or side of the other foot can be moved transversely across the roller 61 in order to rotate it and thereby adjust the amount of wire wrapped around the pulley wheel. Winding more wire around the roller 61 will cause the counterweight means 11 to descend and the body part supporting device 15 to rise, and unwinding the wire around the roller 61 will cause the opposite. Preferably the pulley wheel of the roller 61 has a diameter D which is equal to or greater than 5 cm and equal to or less than 20 cm, more preferably is equal to or greater than 5.5 cm and equal to or less than 15 cm and most preferably is equal to or greater than 7 cm and equal to or less than 11 cm.

The invention also relates to a method for stabilizing the movement of a limb comprising the steps of providing a patient with a device comprising a limb-receiving support operatively connected to a counter-weight and further providing a patient foot-operable auxiliary force provider for adjusting the position of said counterweight.

The embodiments described above are to be understood as illustrative examples of the present invention. It will be understood by those skilled in the art that modifications, combinations and changes may be made to the embodiments without departing from the scope of the present invention. In particular, different part solutions in the different embodiments can be combined in other configurations, where technically possible. The scope of protection of the present inventions is defined by the claims.

Claims

1. Device for stabilizing movement of a limb comprising: a) a frame (3) comprising a substantially upright tube (5) connected at a first end to a base and at a second end to a substantially horizontally-projecting transverse arm (7); b) a counterweight mean (11) slidably mounted in or on the upright tube (5); c) a body part supporting device (15); d) flexible connection means (21) for connecting said counterweight means(ll) to said body part supporting device (15); wherein said body part supporting device (15) is suspendable from said transverse arm (7) by said flexible connection means (21), characterized in that said counterweight means (11) is connected to a foot-operable auxiliary force provider (23) arranged for adjusting the position of said counterweight means (11), and the foot-operable auxiliary force provider (23) is connected to the counterweight means (11) with a wire (32) running via at least one pulley wheel (33; 43; 53; 63).

2. Device according to claim 1 wherein said foot-operable auxiliary force provider (23) is a carriage (31) movable towards and away from said upright tube.

3. Device according to claim 1 wherein said foot-operable auxiliary force provider is a pedal (41; 51) movable towards and away from said upright tube (5).

4. Device according to claim 3 wherein said pedal (41; 51) is pivoted about a top pivot (45), a bottom pivot (55) or an intermediate pivot.

5. Device according to claim 1 wherein said foot-operable auxiliary force provider (23) is a roller (61) rotatable about an axis (A).

6. Device according to claim 5 wherein said axis (A) is substantially horizontal.

7. Device according to claim 5 wherein said axis (A) is vertical or inclined at an angle (a) to the vertical.

8. Device according to any of the previous claims wherein said upright tube (5) is provided with damping means (25) for damping the movement of said counterweight means (11).

9. Device according to any of the previous claims wherein said counterweight means (11) is inside said upright tube (5).

10. Device according to any of claims 1-8 wherein said counterweight means (11) is outside said upright tube (5).

11. Device according to any of claims 8-10 wherein said damping means (25) comprises regulating means (27) for adjusting the damping of the damping means (25).

12. Device according to any of the previous claims wherein said upright tube (5) projects substantially vertically or at an angle equal to or less than 15 degrees from the vertical.

13. Device according to any of the previous claims wherein said transverse arm (7) projects from said base substantially horizontally or at an angle equal to or less than 15 degrees from the horizontal.

14. Device according to any of the previous claims wherein said counterweight means (11) is provided with means for allowing the mass of the counterweight means to be adjusted.

15. Device according to claim 14 wherein said means for allowing the mass of the counterweight means (11) to be adjusted comprises a container for receiving and/or dispensing liquid and/or solid material.

16. Device according to any of the previous claims characterized in that said body part supporting device (15) has a mass preferably equal to or greater than 200 grams and equal to or less than 1.5 kilograms, more preferably equal to or greater than 300 grams and equal to or less than 1.2 kilograms and most preferably equal to or greater than 400 grams and equal to or less than 900 grams.