GB2501368A

GB2501368A - Apparatus for stimulating the trigeminal nerve

Info

Publication number: GB2501368A
Application number: GB1303552.2A
Authority: GB
Inventors: Paula Wood
Original assignee: Smiths Medical International Ltd
Current assignee: Smiths Medical International Ltd
Priority date: 2012-04-21
Filing date: 2013-02-28
Publication date: 2013-10-23
Also published as: GB201207104D0; GB201303552D0

Abstract

An apparatus for relieving breathlessness or dyspnoea comprises a support 5 worn on the head and having means to stimulate a users trigeminal nerve in the region of the cheek on the face by means of a steady or pulsed flow of gas directed to cause slight pressure and a cooling effect, or by means of direct contact with a cooling device or by electrical stimulation with electrodes. A source 1 of forced air from a fan 13 or a compressed gas cylinder may be directed via a flexible conduit 4 and a bore through an arm of a frame 5 similar to spectacles supported on the nose and ears to an outlet 50 located above the user's cheek so that a jet of air is directed downwardly onto the region of the trigeminal nerve TN. The frame 5 could also support a nasal cannula NV. A patient monitor such as a pulse oximeter PO and breathing monitor may control the air supply.

Description

APPARATUS AND METHODS

This invention relates to apparatus and methods.

The invention is more particularly concerned with apparatus and methods for use in relieving breathlessness or dyspnoea (or dyspnea).

Many people suffer from difficult breathing, shortness of breath or breathlessness, known as dyspnoea. This may be as a result of chronic obstructive pulmonary disease (COPD), asthma, lung disease or cardiac disease. Breathlessness can also be experienced by healthy people. such as athletes after exercise, people undergoing arduous physical labour, people climbing or working at high altitude or the like. Common treatments for dyspnoea include the administration of drugs (such as opiates to reduce anxiety or steroids to reduce inflammation in the airway), exercise therapy, or continuous positive airway pressure (CPAP). It has also been found that directing a flow of cooling air from a fan over facial skin can reduce dyspnoea. It is thought that the reduced facial temperature caused by the fan alters feedback to the brain to modify the perception of dyspnoea (DYSPNEA (1999), American Journal of Respiratory and Critical Care Medicine/Medscape Wire. January 21, 1999). In practice, using a fan in this way causes problems because fans tend to be relatively bulky and, although it is possible they could be used while a sufferer is in bed, it would be difficult and for someone who is mobile to carry a fan and place this up to their face when they experience an attack of dyspnoea.

The treatment of dyspnoea using a fan is also described in Dobson, R (2011) "Could a gust of cool air ease breathlessness?", 19th April 2011 [ONLINE] Available from: * http://www.dailymail.co. uklhealthlartiele-1378224/Could-gust-cool-air-ease-breathlessness.html.

It is an object of the present invention to provide an alternative apparatus and method for relieving dyspnoea.

According to one aspect of the present invention there is provided apparatus for relieving dyspnoea including a unit for producing a flow of gas, a flexible gas conduit connected at one end with the unit and head support means adapted to be supported on the user's head, the opposite end of the gas conduit being connected with the head support means, the apparatus including a gas opening on the head support means such that gas flowing through the conduit flows out of the opening, and the gas opening being directed at a localised region of the facial skin in the region of the trigeminal nerve such that the trigeminal nerve is stimulated by gas impinging on the skin.

The unit for producing a flow of gas preferably includes a fan and the gas is preferably air. The head support means may take the form of a frame supported on the user's ears and nose, the gas opening being directed downwardly onto an upper part of the user's cheek. The unit for producing a flow of gas may be arranged to deliver the gas continuously or in pulses. The apparatus may include means for delivering an oxygen-containing gas for breathing by the user, such as a nasal cannula. The apparatus may include means for * monitoring the user, such as a breathing monitor or pulse oximeter, and may be arranged to control the delivery of gas according to the output of the means for monitoring.

According to another aspect of the present invention there is provided apparatus for relieving dyspnoea including a control unit, head support means and stimulation means mounted with the head support means, wherein the head support means is connected with the control unit and arranged to provide localised stimulation of the user's trigeminal nerve in the region of the user's cheek.

The stimulation may be by one or more of: gas flow, thermal contact and electrical contact.

According to a ifirther aspect of the present invention there is provided a method by which a user can himself relieve dyspnoea including the steps of donning head support means connected with a conduit extending to a gas flow source, causing the gas flow source to supply gas via the conduit to an opening on the head support means such that a stream of gas is directed at a localised region of the facial skin in the region of the trigeminal nerve * such that the nerve is stimulated by the gas impinging on the skin.

According to yet another aspect of the present invention there is provided a method by which a user can himself relieve dyspnoea including the steps of donning head support means including a stimulating device arranged to stimulate a localised region of the facial skin in the region of the trigeminal nerve such that the nerve is stimulated by the stimulating device.

The stimulating device may include a cooling device or ar electrode.

According to a fifth aspect of the present invention there is provided apparatus for use in a method according to the above further or yet another aspect of the present invention.

Apparatus and its method of use, according to the present invention, will now be described, by way of example, with reference to the accompanying drawings, in which: Figure 1 illustrates the apparatus schematically on a patient; Figure 2 is a plan view of the gas supply unit of the apparatus; Figure 3 is a side elevation view showing the interior of the gas supply unit; Figure 4 is a plan view of the head support of the apparatus; Figure 5 is a front elevation view of the head support of Figure 4; and Figure 6 is a side elevation view of the head support along the arrow VI of Figure 5.

With reference first to Figure 1, the apparatus comprises a unit 1 for producing a flow of gas, a flexible conduit or tubing 4 connected at one end 41 to an outlet nozzle and connector 10 of the unit and supportcd at its opposite en&42 on a head support 5. The head support 5 has a gas outlet 50 through which gas emerges from the support and is directed downwardly in a stream orjet onto the upper part of the user's cheek, in the region of the maxillary division of the trigeminal nerve TN.

With reference now also to Figures 2 and 3, the unit 1 is preferably portable and wearable, such as on a belt or in a pocket or backpack. The unit 1 has a housing 11 that is about 150mm long, 90mm wide and 70mm deep. A tube 12 of circular section and 24mm internal diameter extends along the length of the housing 11 and supports within it close to one end a DC fan 13. The term "fan" is used to include blowers, impellers and other forms of electrically-driven air movers. A protective wire mesh 14 covers the left-hand inlet end of the tube 12 to prevent debris being drawn into the fan 13. Towards its opposite, right-hand end 15 the tube 12 contains a tapering restriction 16 projecting from the right-hand end face 17 of the housing 11 as the outlet nozzle 10 having an internal diameter of about 4mm. The reduction in cross-sectional area along the restriction 16 to the nozzle 10 means that the air flowing out of the nozzle has a higher velocity than the air flowing along the tube 12 adjacent the fan 13, according to the Bernoulli principle. The fan 13 is connected to a motor control unit 19, which in turn is connected to a battery box 20 containing two rechargeable 9 volt batteries. A potentiometer 21 mounted on the battery box 20 is adjustable during set-up of the unit I to adjust the fan speeds and hence the airflow rates. On its exterior, the housing 11 has an on/off button 22 operable to turn the power of the unit on and off. Three further buttons 23 to 25 are operable by the user to select the fan speed, and hence the airflow rate to one of three different values: low, medium and high. An LED power indicator 26 shows that the unit is fully charged and operating correctly. If the gas flow unit is of a wearable construction it may have an outer layer over its housing, or parts of its housing, of a soft, conformable material such as a silicone both to provide comfort to the user and to reduce slipping along a supporting belt.

Although the gas flow unit I described above takes the form of a fan, it would be * possible to use alternative gas flow units including a canister of compressed gas. The arrangement described above produces a steady, continuous and uninterrupted gas flow but it could readily be modified to produce a pulsed gas flow if this were found to produce an enhanced stimulation effect or reduced discomfort. The pulsed output could be produced by intermittently energising the fan or by interrupting the gas flow from Ihe fan by means of a vibrator, oscillator or the like, such as similar to that described in US658 1598. Alternatively, an air mover with an inherent pulsed output could be used.

The conduit 4 is in the form of a length of flexible PVC tubing having a 4mm internal diameter so that a connector 41 at its inlet end can be push fitted securely onto the outlet conncctor 10 of the gas supply unit 1. Other forms of conventional gas couplings could be used, The outlet end 42 mounted with the head support 5 is also preferably also of 4nun internal diamctcr. The tubing 4 could have the same internal diameter along its entire length but, in order to increase flow rate along the tubing, its internal diameter is preferably increased to 6mm along most of its length. This is achieved by forming the tubing of three separate lengths joined together provided by two short, smaller diameter lengths 4A and 4C at opposite ends and an intermediate longer, larger diameter main portion 4B. The length of the tubing 4 depends on where the gas flow unit 1 is to be supported. The tubing 4 could be of any convenient length, typically being between about 0.5 to 1.5m long. For a unit 1 supported on a beltaround the waist the tubing 4 would preferably be about I 3m long.

With reference now also to Figures 4, 5 and 6, the head support 5 resembles a spectacles frame, having two temple arms 51 and 52 curved at one end 54 to be supported on the user's ears E and attached at their opposite ends to a lens frame 55 with a bridge 56 for supporting on the wearer's nose N. The lens frame 55 need not contain any lens, or it could include lenses of neutral power, prescription lenses matched to the user's requirement, tinted sunglasses lenses, safety lenses, 3D screen lenses or the like. In the present example, only the left-hand temple arm 51 is hinged with the lens frame 55 by a pivot joint 57. The right-hand temple arm 52 is fixed and integral with the lens frame 55. It will be appreciated, however, that both arms could be hinged. The or each temple arm could be hinged by means of a pivot screw or the end of the arm and the lens frame could have cooperating moulded formations that snap into one another to form a pivot joint as is common on some conventional sunglass frames. The right-hand temple arm 52 supports the outlet end 42 of the tubing 4 and, in the present example, the arm is moulded about the end of the tubing, although it could be supported in other ways. Outer ends of the lens frame 55 curve rearwardly following the contours of the face to provide opposite extensions 58. The gas outlet 50 is about 4mm in diameter and is located on the inner surface of the right-hand extension 58 towards its lower side and directed downwardly so that when worn the outlet is spaced above the user's cheek by about 20mm, The gas outlet 50 is connected with the passage through the tubing 4 by a bore 59 moulded in the extension 58. Instead of having a single gas outlet it would be possible to provide two or more outlets located at different points along the trigeminal nerve. The head support 5 may be overmoulded, or overmoulded in parts, with a soft, conformable material such as a silicone to provide a soft, comfortable, non-slip surface contacting the user's skin.

Although the head support has been described as being in the form of a spectacles frame it will be appreciated that alternative supports are possible. For example, the support could be provided on a helmet or headband. Alternatively, the support could be similar to microphone headsets. It will be appreciated that the head support could be arranged to provide two gas streams on opposite sides of the face for maximum effect.

The apparatus may be separated when not in use, with the gas flow unit I being stored on a belt and the head support 5 and associated tubing 4 folded up and stored in a pocket, pouch or bag to protect it from damage and contamination, In use, the user dons the head support 5 and selects the level of air flow required by pressing the appropriate one of the buttons 23 to 25. The low level delivers air at a rate of about 0.5 1/mm, the high level delivers air at a rate of about 1.2 1/mm and the medium level delivers air at a rate of about 0.9 1/mm. The stream of air emerging from the gas outlet 50 is incident on a localised area of the skin in the region of the trigemirial nerve TN. This causes a slight pressure to be exerted on thenerve but mainly a cooling effect because the emerging air is at a temperature lower than body temperature. This stimulation of the trigeminal nerve can reduce dyspnoea in the user without the need for medication.

The apparatus has the advantage that it is readily portable and is unobtrusive. The stimulation is provided where it has most effect and without causing uncomfortable cooling of the remainder of the face. The apparatus is relatively simple and can be made at low cost, requiring minimal maintenance. The simple operation makes the apparatus easy for patients to use themselves at home. The apparatus is particular suitable for patients who cannot tolerate face masks. In addition to helping patients with breathlessness, the apparatus could alsobe used to facilitate recovery of athletes after training or other people who become breathless after extreme exertion or after being exposed to reduced levels of oxygen, such as at altitude.

The apparatus can readily be used in combination with conventional therapies employing a face mask, nasal cannula or hood for delivering an oxygen-containing gas for breathing by the user. The head support of the present invention could be used to support a nasal cannula, such as the nasal cannula NV shown in Figure 1.

The cooling effect could be increased by designing the gas outlet so that it provides a slight restriction thereby causing a pressure drop across the outlet as the air emerges and a consequent temperature drop. The cooling effect could alternatively or additionally be increased by including some form of cooling within the gas flow unit, such as an active cooler or thermal mass cooled externally, such as in a freezer, and then placed in the air flow path of the unit.

Instead of stimulating the trigeminal nerve by an impinging gas stream it might be possible to stimulate it in other ways such as by direct contact with a cooling device, such as a thermoelectric junction or a conductive surface in contact with a cooling liquid.

Alternatively, it might be possible to stimulate the nerve electrically by contacting the skin surface.with an electrode connected to a source of low power de or alternating current.

The apparatus could include feedback from some form of patient monitor such as the pulse oximeter P0 shown in Figure 1, or a breathing sensor. A pulse oximeter could be clipped onto a finger or could conveniently be clipped onto an ear so that the cable from the pulse oximeter could extend along the tubing 4. Any such pulse oximeter or breathing sensor could be arranged to turn off the apparatus when the feedback indicates that the patient is breathing normally or has normal oxygen saturation levels, in order to conserve battery power. Alternatively, the feedback could be arranged to turn on the apparatus or increase the flow rate when the feedback indicates that the patient may be suftèring dyspnoea.

Claims

CLAIMS1. Apparatus for relieving dyspnoea including a unit (1) for producing a flow of gas, a flexible gas conduit (4) connected at one end with the unit (1) and head support means (5) adapted to be supported on the user's head, wherein the opposite end of the gas conduit (4) is connected with the head support means (5), wherein the apparatus includes a gas opening (50) on the head support means (5) such that gas flowing through the conduit flows out of the opening (50), and wherein the gas opening (SO) is directed at a localised region of the facial skin in the region of the trigeminal nerve (TN) such that the trigeminal nerve is stimulated by gas impinging on the skin.
2. Apparatus according to Claim 1, wherein the unit(1) for producing a flow of gas includes a fan (13).
3. Apparatus according to Claim 1 or 2, wherein the gas is air.
4. Apparatus according to any one of the preceding claims, wherein the head support means takes the form of a frame (5) supported on the user's ears (E) and nose (N), and wherein the gas opening (50) is directed downwardly onto an upper part of the user's cheek.
5. Apparatus according to any one of the preceding claims, wherein unit (1) for producing a flow of gas is arranged to deliver the gas continuously.
6. Apparatus according to any one of Claim 1 to 4, wherein the unit (1) for producing a flow of gas is arranged to deliver the gas in pulses.
7. Apparatus according to any one of the preceding claims including means (NY) for delivering an oxygen-containing gas for breathing by the user.
8. Apparatus according to Claim 7, wherein the gas delivering means is a nasal cannula (NV).
9. Apparatus according to any one of the preceding claims including means for monitoring the user (P0).
10. Apparatus according toClaim 9, wherein the means for monitoring includes one or both of a breathing monitor and a pulse oximeter (P0).
11. Apparatus according to Claim 9 or 10, wherein the apparatus is arranged to control the delivery of gas according to the output of the means for monitoring (P0).
12. Apparatus for relieving dyspnoea including a control unit (1), head support means (5) and stimulation means (50) mounted with the head support means (5), wherein the head support means (5) is connected with the control unit (1) and arranged to provide localised stimulation of the user's trigeminal nerve (TN) in the region of the user's cheek.
13. Apparatus according to Claim 12, wherein the stimulation is by one or more of: gas flow, thermal contact and electrical contact.
14. Apparatus substantially as hereinbefore described with reference to the accompanying drawings.
15. A method by which a user can himself relieve dyspnoea including the steps of donning head support means (5) connected with a conduit (4) extending to a gas flow source (1), causing the gas flow source (1) to supply gas via the conduit (4) to an opening (50) on the head support means (5) such that a stream of gas is directed at a localised region of the facial skin in the region of the trigeminal nerve (TN) such that the nerve is stimulated by the gas impinging on the skin.
16. A method by which a user can himself rclieve dyspnoea including the steps of donning head support means (5) including a stimulating device (50) arranged to stimulate a localised region of the facial skin in the region of the trigeminal nerve (TN) such that the nerve is stimulated by the stimulating device.
17. A method according to Claim 16, wherein the stimulating device includes a cooling device or an electrode.
18. A method of relieving dyspnoea substantially as hereinbefore described with reference to the accompanying drawings.
19. Apparatus for use in a method according to any one of Claims 15 to 18.