Field of Invention

The invention relates to the careful attachment of a clip to the human body. In particular, the present invention relates to the attachment of electrodes to the tragus by a clip.

Background

In medicine, there is research about the benefits of vagus nerve stimulation and increasing use in clinical practice. The benefits may include enhanced recovery from stroke or other neuroplasticity benefits, treatment of epilepsy, treatment of depression, treatment of anxiety, treatment of autonomic nervous system disorders, and potentially other applications.

There are clinical applications involving surgical implantation of electric stimulators and electrodes around the vagus nerve in the neck. There are also applications wherein a branch of the vagus nerve is stimulated where it sits in the tragus, a lobular part of the ear, adjacent to the ear canal. Non-invasive vagus nerve stimulation, through intact skin is known as transcutaneous vagus nerve stimulation (TVNS). Figure 1 shows the location of the tragus (10) alongside a tragus clip (15) of the prior art.

In the prior art for TVNS there are numerous spring-loaded clips in use, most operate akin to a clothes peg, with one or two electrodes at one end, and wires at the other end. These prior art clips are intended to hold electrodes to the tragus for the purpose of TVNS. Examples of clips in the prior art are depicted in figure 2.

The tragus is a small, tapered part of the ear, and it is not easy to get a good attachment of electrodes in this site. There are many anatomical variations in size and shape between normal people and inevitably spring-loaded clips tend to be too tight, or too loose to achieve a secure and comfortable fit. Clips that are too loose will usually fall off, especially if the subject is moving about. Clips that are too tight may cause skin injury, especially if the application is prolonged, or may be uncomfortable.

Clips for this application are usually small, such as the prior art clips (20), with electrode (21 ) and (22), with electrode (22) is shown in figure 2; smaller than a clothes peg, and the springs involved, (25) and (26) respectively, are too small and delicate to be readily manipulated or adjusted by the user to achieve the desired tension and clip force. Unwanted pulling or dragging forces from the attached cables (27) of the prior art clip (21) exacerbate the difficulties in achieving a secure and comfortable attachment.

Many users will prefer to use a commonly available transcutaneous electrical nerve stimulator (TENS) device in combination with an electrode clip sized for the ear. However, the small electrodes sometimes do not match the usual impedance and load requirements for stable operation of the TENS device and so are not always compatible. Without improvements, these TENS devices may lack proportional control.

Object of the invention

It is an object of the invention to create a device that allows a safe, comfortable, and secure attachment of a pair of electrodes to the tragus for the purpose of TVNS with commonly available TENS devices.

It is an object of the present invention to overcome, or at least substantially ameliorate, the disadvantages and shortcomings of the prior art.

Other objects and advantages of the present invention will become apparent from the following description, taking in connection with the accompanying drawings, wherein, by way of illustration and example, an embodiment of the present invention is disclosed.

The advantages of the invention may apply to other attachments to the human body, or any other application where careful attachment of a clip is a requirement.

Summary of Invention

A magnet sprung clip electrode device wherein opposing magnets produce the closing force of the clip.

In preference there is at least a third magnet allowing the closing force of the clip to be adjusted.

In preference there is at least a fourth magnet allowing the closing force of the clip to be further adjusted.

Wherein the clip holds electrodes to the skin.

Wherein the electrode cable exit points are adjacent the electrode contact points.

Wherein an adjustable wire hook optionally attaches adjacent to the electrode contact points. Wherein there is a dummy load electrically connected between the electrodes.

In preference, the electrodes are made of electro-conductive plastic or rubber, with a metal core that is contained.

In preference the device is used for the purpose of TVNS.

Description of the Drawings

An embodiment of the invention will now be described, by way of example only, with reference to the accompanying drawings in which:

Figure 1 illustrates the tragus as a site for clip electrode attachment for TVNS;

Figure 2 illustrates spring clips of the prior art with electrodes, springs, and cables;

Figure 3 illustrates an embodiment of the invention in side view, with magnets;

Figure 4 illustrates an embodiments of the invention with multiple magnet positions, with figure 4a showing use of the two embedded magnets in combination with two movable magnets on the inside of the arms, figure 4b showing use of the two embedded magnets in combination with one movable magnet, figure 4c showing use of the two embedded magnets in combination with two movable magnets on the outside of the arms, figure 4d showing use of the two embedded magnets in combination with one movable magnet on the outside of one arm, and figure 4e only the two embedded magnets;

Figure 5 illustrates an embodiment of the invention and the electrode cable exit positions;

Figure 6 illustrates attachment of an adjustable wire hook;

Figure 7 illustrates a schematic for simple dummy load electrically attached between electrodes;

Figure 8 shows an embodiment where ethe dummy load is a single resistor;

Figure 9 shows an embodiment where the with a resistor-capacitor load between connector sockets;

Figure 10 shows an embodiment with a constant current load between connector sockets;

Figure 11 shows an embodiment of a dummy load integrated with electrode clip assembly; Figure 12 shows an embodiment of a dummy load in a wiring loom.

Detailed description of the invention

With reference to figures 3 to 6 an embodiment of the present invention is described

Referring firstly to figure 3, the clip (30), shown in a closed position, includes an insulating plastic clip body 35 having arms (36a) and (36b), a pivot axle (40), conductive plastic electrodes (45a) and (45b), electrical contacts (50a) and (50b) for the attachment of electrode cables. Each of the arms (36a) and (36b) has an inside face (38a) and (38b) respectively and an outside face (41a) and (41b) respectively. Embedded magnets (55) located at the first inner side (38a) and (38b) at first ends (61 a) and (61 b) of the arms (36a) and (36b), moveable magnets (71a) and (71b) are located on the outer sides (41a) and (41b). Magnets (71a) and (71 b) are movable in that they are not permanently embedded, irreversibly secured or affixed to their locations on the arms (36a) and (36b).

In figure 3, the embedded magnets (55a) and (55b) located on the first ends (61a) and (61b) are oriented such that they repel each other, causing a closing force on the clip (30) and the first arm (36a) and second arm (36b) pivoting about the pivot axle (40) urging the electrodes (45a) and (45b), positioned on the inside of the second ends (80a) and (80b) of each arm (36a) and (36b), together. The pivot axle (40) in the present embodiment includes each arm (46a) and (46b) having a lug projecting from the inner face (38a) and (39b) respectively, each lug having a aperture though which a pin or retaining means, such as a screw or other such suitable retaining means located within, to allow the first arm (36a) and second arm (36b) to be pivotably connected to each other.

The clip (30) can easily be opened by hand, pushing the magnets (55a) and (55b) closer by applying force to the outside faces (41a) and (41b) of the first ends (61a) and (61 b) of the arms (36a) and (36b), in a pinching motion, together thus separating the electrodes (45) in preparation to position around the skin of the tragus. The clip (30) can be constructed from any material suitable for the production of such items, such as, but not limited to, plastics, injection moulded plastics, or 3D printed plastic materials, each of which are known to those skilled in the art.

The moveable magnets (71a) and (71 b) can be arranged in different combinations such that their number, and proximity relative to each other and the magnets (55a) and (55b) varies. The more moveable magnets (71a) and (71 b), and the closer their proximity, the greater the repulsive force, and the greater the urging of the first ends (61a) and (61b) away from each other, and the stronger grip that the clip (30) exerts between the second ends (80a) and (80b). For example, a non-limiting sample of different combinations is illustrated in figure 4.

Figure 4a, for example, shows an arrangement of the clamp (30) with the magnets (55a) and (55b) and the moveable magnets (71a) and (71 b) located on the inner sides (38a) and (38b), wherein this embodiment exhibiting greatest repulsion force and hence the highest clamping force between the second ends (80a) and (80b). Figure 4b shows an arrangement of the clamp (30) with the magnets (55a) and (55b) and only one of the moveable magnets (71a) and in place. This arrangement has less repulsive force that that of the arrangement shown in figure 4a, and thus exerts less clamping force between the second ends (80a) and (80b).

Figure 4c shows an arrangement of the clamp (30) with the magnets (55a) and (55b) and the two movable magnets (71a) and (71b) positioned on the outer sides (41a) and (41b). As the proximity of the two movable magnets (71a) and (71 b) are further away from one another compared to the arrangement shown in figure 4a, the repulsive force is less than that of 4a. Figure 4d shows an arrangement were just one of the movable magnets (71a) is located on the clamp (30), in combination with the two embedded magnets (55a) and (55b) this then provides less repulsive force compared to the arraignment show in figure 4b.

The arrangement of 4e is the softest or most gentle force, with no movable magnets being used, only the two embedded magnets (55a) and (55b). The examples of combinations shown is not exhaustive, as it is also possible to add a mix of larger/thicker magnets and smaller/thinner ones, or magnets of varying strength, or combination thereof to further adjust the desired force if necessary.

These combinations are easily set up by the user and can be used to tune the required grip of the clip to the user requirements depending usually on the size and shape of the tragus, sensitivity of the skin, and activity level for that individual during use.

In addition to adjustable clip force, the ability to achieve a secure fit is improved by the position of the electrode cable exits. In the prior art, the cables are routed through the clip and exit at the farthest point from the electrode end; refer figure 2b for an example. The routing shown in prior art figure 2b creates a long lever arm for any cable dragging forces to twist the clip and move it from the desired position on the ear. In the preferred embodiment, the clip (30) has the electrode cables (90a) and (90b) exit at (50) close to the electrode contact point(44) of the electrodes (45a) and (45b). This position minimises the leverage that any cable pulling exerts on the contact points and reduces the tendency for the clip to twist and shift. A cable exit position is further illustrated in figure 5 with the cables (90a) and (90b) exiting from the arms (36a) and (36b).

Figure 5 illustrates the position of a metal screw (89) on the arm (36a) of the clip (30), there being a similar screw on the other arm (36b), that makes electrical contact with the electrode cable, embeds most of the way through the electrode body, and helps conduct electricity near to the electrode contact point 44 of the electrodes (45a) and (45b), thus enhancing the electrical distribution through the plastic or rubber electrode. Electroconductive plastics and rubbers are available during manufacturing but the usual conductivity is not great, and the presence of a metal core allows the electrodes to be thicker, or shaped as per figure 3 without suffering high impedances.

In addition to the adjustable clip force, in cases where the tragus is especially difficult to grip, an adjustable support means, for example, wire (100) can be attached, close to the electrode contact point (44) of the clip (30) as shown in figure 6. The wire (100) is attached to the clip (30) adjacent to the electrode contact points (44) of the electrodes (50a) and (50b) and is easily bent to match the shape and dimension of the user’s ear. For added comfort, the wire may be covered in soft and flexible material. Curved profiles that sit over the ear to provide mechanical support and enhance a secure fit for some apparatuses with the wire being highly adjustable, and can be positioned adjacent to the electrode contact point (44) which is a unique implementation of the mechanical support principle in the context of TENS or TVNS.

To match the electronic impedance requirements of some common TENS devices, a dummy load can be utilised. For example, as shown in figure 7, the TENS device (120) is connected between the electrode cables (125a) and (125b). In order to keep the clip small, the electrical connection can be made at the ends (135a) and (135b) on the clip body (138) of the electrode cables (125a) and (125b), adjacent to where the TENS device cables attach at locations (130a) and (130b). In the preferred embodiment, the load may be a simple resistor (140). Other more sophisticated loads may be employed including resistor-capacitor networks per figure 8 or constant current loads per figure 9.

Commonly available TENS devices are often used to apply TVNS, however, they have usually been designed and specified to work with larger electrodes and different load impedances. The tiny ear clip electrodes utilised in TVNS may not have the required impedance for the TENS device to operate normally. Without improvements, these TENS devices may lack proportional control. To better match the electronic impedance requirements of some common TENS devices, in certain embodiments a dummy load is connected between the electrode cables.

In order to keep the ear clip small, the electrical connection to the dummy load can be made at the connector end of the electrode cables, adjacent to where the TENS device cables attach via plug and socket. Alternatively, it is possible to add a loaded wiring loom that plugs into the connector end of the electrode assembly. A loaded writing loom can also be used to improve the impedance characteristics of electrodes that do not have a built-in dummy load.

The use of dummy or synthetic loads is new in the context of a small electrode optimised for TVNS for a TENS device.

In the preferred embodiment, the load may be a simple resistor, as show in figure 8. Other load types may be employed. Example of a resistor-capacitor network is illustrated in figure 9 and constant current loads in figure 10. Figure 11 shows an example of a dummy load integrated with electrode clip assembly that can be used in an embodiment of the present invention. Figure 12 shows a dummy load in a wiring loom that can be used in an embodiment of the present invention.

A. An apparatus when used for attachment of electrodes to the tragus, the apparatus including: a. a body having a first clamp arm and a second clamp arm pivotally engaged with each other, b. the first clamp arm and the second clamp arm each having an embedded magnet located at a first end and a conductive electrode at a second end, c. wherein each of the embedded magnets located at the first ends of the first clam arm and second clamp arm acting to repel each other urging the second ends of the clamp arms towards one another to transmit a clamping force to the conductive electrodes

B. The apparatus of A, further characterised in that first clamp arm includes at least a first moveable magnet in close proximity to the embedded magnet on the first clamp arm to adjust the force exerted on the conductive electrodes.

C. The apparatus of A or B, further characterised in that there is at least a second moveable magnet located on the first end of either the first clamp arm or second clamp arm to increase the clamping force exerted on the conductive electrodes. D. The apparatus of any one of the above, further characterised in that there is at least one electrode cable exit point positioned adjacent to the conductive electrodes to attach at least one electrode cable.

E. The apparatus of any one of the above, further characterised in that the conductive electrodes are constructed from an electro conductive plastic or rubber with a metal core that is electrically connected to the at least one electrode cables.

F. The apparatus of any one of the above, further characterised in that there are two electrode cables, each one electrically attached to a respective conductive electrode in each of the first clamp arm and a second clamp arm.

G. The apparatus of any one of the above, further characterised in that an adjustable support means is removably connected to the apparatus body.

H. The apparatus of any one of the above, further characterised in that the adjustable support means is a flexible adjustable support means, in particular a flexible wire.

I. The apparatus of any one of the above, further characterised in that there is a dummy load electrically connected between the electrode cables.

J. The apparatus of any one of the above, further characterised in that the apperatus is a TENS device.

K. A dummy load when used for a TENS device of any one of the above A-J.

L. A dummy load, the dummy load being operatively connected to a TENS device, wherein the TENS device includes an electrode optimised for TVNS.