GB2530903A

GB2530903A - Respiratory therapy devices

Info

Publication number: GB2530903A
Application number: GB1515453.7A
Authority: GB
Inventors: Anthony Lucio Belisario; Robert James Burchell; Mohammad Qassim Mohammad; Mark Charles Oliver; Mark Sinclair Varney
Original assignee: Smiths Medical International Ltd
Current assignee: Smiths Medical International Ltd
Priority date: 2014-10-03
Filing date: 2015-08-29
Publication date: 2016-04-06
Also published as: GB201515453D0; GB201417482D0

Abstract

A respiratory device 100 is disclosed in which the frequency of movement, between two positions, of a flow obstructing and enabling valve 20, is independent of respiratory pressure exerted by a patient. This may be the opposite to the normal mode of operation of common current devices, and may have advantages in the simplicity of operating the device, for which a clinician may wish to accurately set the frequency.

Description

RESPIRATORY THERAPY DEVICES

This invention relates to respiratory therapy devices.

Positive expiratory pressure (PEP) devices, that is, devices that present a resistance to expiration through the device, are now widely used to help treat patients suffering from a range of respiratory impainnents, such as chronic obstructive pulmonary disease (COPD), bronchitis, cystic fibrosis and atelectasis. More recently, such devices that provide an alternating resistance to flow have been found to be particularly effective. One example of such a device is sold under the trade mark Acapella (a registered trade mark of Smiths Medical) by Smiths Medical and is described in US658 1598, US6776 159, 1357059324 and US7699054. US8025054 and US8534284 describe a device with an interrupter valve driven by expired gas from the patient that is delivered to the apparatus. The speed of the valve is dependent on the back pressure created by expired breaths from the patient. Other vibratory respiratory therapy devices are available, such as "Quake" manufactured by Thayer, "Aer0PEP" manufactured by Monaghan, "TheraPEP" manufactured by Smiths Medical and "IPV Percussionator" manufactured by Percussionaire Cog,. These devices generate vibratory positive pressures mechanically and fluctuating exhalation flows that help overcome the inertia and stiction of the sputum within the bronchi and lower passages of the lung. This enhances mucociliary clearance. Alternative apparatus such as "CoughAssist" manufactured by Philips is also available.

Some respiratory therapy devices can provide an alternating resistance to flow during inhalation.

One possible probJem with some of these devices is that the frequency of vibration is dependent on the expiration force exerted by the patient and this is not necessarily the optimum frequency for most effective treatment.

Furthermore, the frequency of operation, the resistance and flow through previous devices cannot be easily altered independently. Also, the waveform of the baa pressure and flow pulse applied to the patient cannot be altered. Furthermore, these settings are dependent on the flow produced by the patient. So, although these devices can be very effective, clinicians are often unsure of the most effective setting for the frequency of the vibratory pulse or the restriction required providing optimum therapy performance for that particular patient with their specific condition at that specific time, Also, because the vibratory frequency is often linked inextricably with the change of exhalation flow rates and the restriction provided by the device it is difficult to know which parameters are more important and those that can be compromised to provide the most effective therapy.

The effectiveness of treatments by such Vibrating Positive Expiratory Pressure (V-PEP) devices is thought to be critically dependent on the frequency, pressure, amplitudes and shape of the generated vibration or pulses. PCT/0B20 15/000097 describes a V-PEP device with a rotating vane driven by an electrical motor, the speed of which is independent of expiratory flow.

It is an object of the present invention to provide an alternative respiratory therapy device.

According to the present invention there is provided a respiratory therapy device arranged to produce an alternating resistance to respiratory flow through the device, the device including a gas passage and means movable relative to the gas passage to obstruct or enable gas flow through the passage, the movable means being arranged to be displaced between obstructing and enabling positions by a flow of an independent pressurised gas supplied to the device, and the frequency of movement between the two positions being substantially independent of respiratory pressure exerted by the patient during use of the device.

The movable means may be a pivoted flap. The device may include a turbine driven by flow of the pressurised gas supplied to the device, the turbine being coupled with the movable means, The device preferably includes a housing within which the turbine is located, the housing having an inlet by which the pressurised gas is supplied to the housing, the housing having a flow path to an atmospheric inlet through which the patient inhales. The respiratory therapy device may be arranged to provide an elevated positive expiratory pressure (PEP) from gas supplied to the device. The pressurised gas supplied to the device preferably contains oxygen at higher concentration than atmospheric levels. The pressurised gas supplied to the device may be used both to drive the movable means and to provide supplementary oxygen to the patient. The device is preferably an expiratory therapy device and may include two pressure relief valves that open to allow gas at pressure to escape from the device, the two pressure relief valves being located on opposite sides of the movable means, the valve located on the downstream side of the movable means relative to the expiratory flow opening at a lower pressure than the other valve.

A V-PEP device according to the present invention will now be described, by way of example, with reference to the accompanying drawing, which is a schematic side elevation view of the device.

The respiratory therapy device 100 comprises a housing I and patient interface 2, such as a mouthpiece or face mask fitted onto the left-hand end of the housing. The housing 1 has a tubular gas flow passage 3 extending internally along it. Towards the end opposite the patient interface 2 the housing 1 has an inlet chamber 10 with an opening 11 to atmosphere. The inlet chamber 10 communicates with the gas passage 3 along the housing I via a one-way valve 13 that opens when gas pressure in the inlet chamber exceeds that in the gas passage and closes when the pressure in the housing exceeds that in the inlet chamber.

The device 100 also includes two pressure relief valves 15 and 16. One valve 15 opens into the housing I at a location close to the patient interface 2. This valve 15 allows air to flow out from the gas passage 3 when pressure within the housing 1 is relatively high; it prevents any gas flow into the housing through it in the opposite direction. The other valve 16 is located towards the opposite end of the device 100, that is, at the downstream end of the device relative to expiratory flow, at the outer end of a short side port 17. The valve 16 also allows air to flow out from the housing 1 when pressure inside it is above atmosphere. The pressure at which the second valve 16 opens is lower than that of the first valve 15 so air preferentially flows out through the second valve except when passage through this valve is obstructed. Again, the second valve 16 prevents any substantial air flow into the housing 1 from atmosphere through the valve. The second valve 16 sets the PEP value; the first valve acts as a pressure relief valve.

The device 100 includes movable means in the form of a displaceable flap member 20 pivotally mounted in the housing I, the two pressure relief valves 15 and 16 being located on opposite sides of the flap member. The flap member 20 is displaceable between two positions. In the first position shown in the drawing by the solid line, the lower edge 21 of the flap 20 engages with an edge 22 of the side port 17, that is, between the side port and the patient interface 2 so as to obstruct or block the side port and thereby reduce expiratory flow out through the downstream valve 16. This has the effect of raising the internal pressure in the gas passage 3. With the flap 20 in this position and the second valve 16 obstructed, the first valve 15 vents any excessively high pressure exerted by the

S

patient. In the second position, shown by the broken line, the lower edge 21 of thç flap 20 disengages the seal 22 of the side port 17 so that the side port is open to enable flow along the gas passage 3 from the patient interface 2 and out through the valve 16.

The flap 20 is urged to its open position (shown by the broken line) by a spring or other resilient means 24 located in the inlet chamber 10. The force applied by the spring 24 to the flap 20 can be adjusted by a knob or other manual control 25 accessible externally of the device 100. The inlet chamber 10 also includes a drive mechanism 30 for displacing the flap 20 between its open (enabling) position and its closed (obstructing) position. In particular, the drive mechanism is a pneumatic, gas-powered mechanism 30. The mechanism 30 is mounted within a turbine housing 130 and includes a turbine 31 with multiple vanes 32 (there would typically be more than the four vanes shown in the drawing, which is schematic only). The turbine 31 is rotatable about an axis 33 extending transverse to the housing I. The turbine 31 is arranged to be coupled with the flap 20, such as by means of a cam (not shown) on the turbine shaft that engages the upper end 34 of the flap 20, which projects into the turbine housing 130. The turbine 31 is mounted with its periphery aligned with a gas inlet 12 into the turbine housing 130. The gas inlet 12 is connected via an adjustable throttle 36 and conduit 37 to a source of gas pressure 38, preferably a source of regulated, pressurised gas containing oxygen at a higher than atmospheric concentration, such as pure oxygen. This may be provided by a cylinder of compressed gas or a hospital oxygen supply. Alternative gases could be used, such as containing other therapeutic gases, for example, oxygen and helium mixtures. Gas flows out of the gas inlet 12 into the turbine chamber 130 and is directed onto the vanes 32 of the turbine 31 so as to rotate it in an anticlockwise sense. As the turbine 31 rotates its earn engages and displaces the upper end 34 of the flap 20 to the right against the action of the spring 24, thereby displacing the lower end 21 of the flap to the left, to the closed position. As the cam moves past and clears the flap the spring 24 pushes its upper end 23 to the left so that the lower end 21 snaps back to the open position. The flap 20 repeatedly moves back and forth between open and closed positions, thereby alternately opening and closing the expiratory path through the device via the valve 16. This provides an alternating obstruction to expiratory flow through the device of the kind that can assist patients with certain respiratory problems. The frequency of oscillation is independent of the force of expiratory pressure exerted by the user, which can be an advantage. The frequency instead is controlled by adjusting the setting of the throttle 36 (to control the gas force applied to the turbine) and, or alternatively, by adjusting the setting of the spring control 25 to alter the restoring force applied to the flap 20.

The gas supplied to the device via the inlet 12 flows into the turbine housing 130 from where it flows out through a variable restrictor 39 to atmosphere. The turbine housing 130 also has a fixed restrictor flow path 40 into the inlet chamber 10. In this way, the pressurised gas supplied to the inlet 12 mixes with atmospheric gas inhaled by S user through the inlet 11. It will be appreciated that the gas supplied to the inlet 12 can be used to alter the gas mixture inhaled by the patient, such as by increasing its oxygen content in order to make breathing easier for patients, which may be particularly needed when the patient is required to undergo the additional respiratory effort involved in using the therapy device 100.

Using gas to drive operation of an oscillatory therapy device in this way has several advantages. First, it readily enables supplementary oxygen or other therapeutic gas to be administered, The device also enables PEEP function to be provided. The frequency of operation of the device can be controlled independently of the patient's expiratory pressure. The device can be used independently of any electrical source.

The device could be modified to provide inspiratory respiratory therapy instead of the expiratory therapy described above.

Claims

CLAIMSA respiratory therapy device arranged to produce an alternating resistance to respiratory flow through the device, wherein the device includes a gas passage (3) and means (20) movable relative to the gas passage to obstruct or enable gas flow through the passage, wherein the movable means (20) is arranged to be displaced between obstructing and enabling positions by a flow of an independent pressurised gas (38) supplied to the device, and wherein the frequency of movement between the two positions is substantially independent of respiratory pressure exerted by the patient during use of the device.
2. A respiratory therapy device according to Claim I, wherein the movable means is a pivoted flap (20).
3. A respiratory therapy device according to Claim 1 or 2, wherein the device includes a turbine (30) driven by flow of the pressurised gas (38) supplied to the device, and wherein the turbine (30) is coupled with the movable means (20).
4. A respiratory therapy device according to Claim 3, wherein the device includes a housing (130) within which the turbine (30) is located, wherein the housing (130) has an inlet (12) by which the pressurised gas (38) is supplied to the housing, and wherein the housing (130) has a flow path (40) to an atmospheric inlet (11) through which the patient inhales.
5. A respiratory therapy device according to any one of the preceding claims, wherein the device is arranged to provide an elevated positive expiratory pressure (PEP) from the gas (38) supplied to the device.
6. A respiratory therapy device according to any one of the preceding claims, wherein the pressurised gas (38) supplied to the device contains oxygen at a higher concentration than atmospheric levels.
7. A respiratory therapy device according to Claim 6, wherein the pressurised gas (38) supplied to the device is used both to drive the movable means (20) and to provide supplementary oxygen to the patient.
8. A respiratory therapy device according to any one of the preceding claims, wherein the device is an expiratory therapy device.
9. A respiratory therapy device according to Claim 8, wherein the device includes two pressure relief valves (15 and 16) that open to allow gas at pressure to escape from the device, wherein the two pressure relief valves are located on opposite sides of the movable means (20), and wherein the valve (16) located on the downstream side of the movable means (20) relative to expiratory flow opens at a lower pressure than the other valve (15).
10. A respiratory therapy device substantially as hereinbefore described with reference to the accompanying drawing.
II. Any novel feature or combination of features as hereinbefore described,