WO1997018846A1

WO1997018846A1 - Nebulizing device

Info

Publication number: WO1997018846A1
Application number: PCT/NL1996/000457
Authority: WO
Inventors: Johannes Hubertus Jozef Maria Kelders; Erwin Petrus Boes
Original assignee: R + D Injector Ag
Priority date: 1995-11-17
Filing date: 1996-11-18
Publication date: 1997-05-29
Also published as: NL1001682C2

Abstract

The invention relates to a device (1) for dispensing a liquid such as for instance ink, a pharmacon or prophylactic, provided with a reservoir (5) for the liquid, an outlet opening (4) connected to the reservoir (5) and nebulizing means (6) arranged between the reservoir (5) and the outlet opening (4). The nebulizing means (6) are connected controllably to electronic control means (8) and are adapted to distribute the substance in separate, very small droplets (16), preferably with a precisely determined droplet size. The nebulizing means (6) herein comprise an inkjet printer element, for instance a piezoelectric element or a bubble-jet element. Using such a device the active substance can be administered in a medical application in practically monodispersed manner, whereby the efficiency of the administering is considerably improved. In addition, such a device is very suitable as for instance drawing instrument with adjustable line thickness.

Description

Nebulizing device

The invention relates to a device for dispensing a liquid such as for instance a pharmacon or prophylactic, provided with a reservoir for the liquid, an outlet opening connected to the reservoir and nebulizing means arranged between the reservoir and the outlet opening. Such a device is known and can be used for instance for administering active substances via the respiratory system to users or patients. What can be particularly envisaged here is the treatment or prophylaxis of respiratory disorders such as for instance asthma. The known nebulizing devices can be sub-divided into four main types .

The most important known nebulizer is the so- called metered dose inhaler or MDI . This is in fact an aerosol filled with the active substance having a dispensing cap and a mouthpiece, whereby each time the aerosol is operated a determined fixed dose of the active substance is nebulized and sprayed out via the mouthpiece. The user herein places the mouthpiece in his mouth or nose or at a distance in front of them and operates the aerosol while simultaneously inhaling the spray flowing out of the aerosol . This MDI has a number of drawbacks. Thus the size of the droplets forming the spray is not distributed relatively uniformly and iε difficult to control. Furthermore, due to the great speed with which the spray leaves the MDI a significant part thereof deposits against the rear wall of the oral cavity of the user and does not therefore reach the lungs where the nebulized substance could be active. In addition, the thus formed spray becomes very cold due to evaporation of the propeilant gas, which is perceived by the user as unpleasant. Finally, many users have problems coordinating their breathing with the operation of the MDI. Another known nebulizing device which is suitable for nebulizing a dry substance consists of a housing in which can be received ampoules with the dry substance which can be carried in front of an outlet opening by the user, for instance by mutually rotating parts of the housing, whereafter the user can draw in the substance simply by inhaling. This known device has the drawback that the operation greatly depends on the manner of breathing of the user, since a sufficient suction is required for nebulizing. Very young or very old users in particular can often not use this device properly.

In yet another known nebulizing device, the so- called jet nebulizer, a liquid active substance is sucked along and nebulized by the ejector action of an air stream under high pressure which is directed practically transversely of the inhaling direction of the user. This device has the drawback that relatively voluminous and high-power equipment is required to generate sufficiently high air speeds to achieve the desired ejector action. In a variant of this device, the ultrasonic nebulizer, the liquid active substance is nebulized and carried in the air stream to the user by deforming the bottom of a reservoir with a piezoelectric element which receives an ultrasonic signal. This device also requires much power. In the nebulizing of a pharmacon or prophylactic it is of great importance that the droplet size can be determined within very narrow limits. It is thus known that due to variations in the droplet size the efficiency of administering of the active substance can be very adversely affected. The mean efficiency of the above described systems amount to 10 to 20%. This implies that 80 to 90% of the supplied active substance does not reach the lungs of the user and is therefore has no effect, or hardly so. A great wastage hereby occurs of often costly active substances, while moreover the possible side effects of the active substances may occur to a more pronounced degree since five to ten times the necessary amount is administered. Two causes can be given for the low efficiency of systems wherein the droplet size is not well controlled. It has been found from research that when the droplets become too large, they cannot follow changes in direction of the inspired air m the respiratory system. The droplets go off the road as it were and thus remain behind in the walls of the oral or nasal cavity and respiratory system. Nor do droplets which are too small reach the lungs either, because during the transport through the respiratory system they are scattered by collisions with for instance air molecules. It is therefore the intention in the nebulizing device to form droplets of equal size, so-called monodispersed droplets, m order to thus increase the efficiency of the device To this end the invention has for its object to provide an improved nebulizing device of the above described type. The nebulizing device according to the invention is distinguished in that the nebulizing means are connected controllably to electronic control means and are adapted to distribute the substance in separate, very small droplets. Due to the electronic control of the nebulizing means a very precise nebulizing can be performed. Nebulizing is preferably performed with a precisely determined droplet size. Practically monodispersed droplets are herein obtained.

A structurally simple embodiment of the invention which can be manufactured at low cost is obtained when the nebulizing means comprise at least one Inkjet printer element. Such printer elements are commercially available on a large scale and operate very accurately and reliably.

A piezoelectric element as well as a bubble-jet element can be considered suitable as printer element. In order to make the device suitable for nebulizing different active substances the electronic control means are preferably adapted to adjust the droplet size. The device can thus be adapted in simple manner to the substance required for a specific user. A problem of known nebulizing devices is that many users have difficulty in coordinating their breathing with the operation of the nebulizing device. It is important that the user inhales at the moment the nebulized substance enters his oral cavity. Preferably arranged therefore in the vicinity of the outlet opening are pressure detecting means which are connected in signal-generating manner to the control means and the control means are adapted to switch on the nebulizing means after receiving a determined pressure signal from the pressure detecting meanε. The nebulizing means can thus be operated automatically when the user inhales, whereby a determined pressure, generally an underpressure, is created. In order to make the device suitable for repeated use the reservoir is preferably exchangeable and/or refillable.

Because the nebulizing means can be embodied compactly by applying a standard printer head, the reservoir, the nebulizing meanε and the control meanε can preferably be accommodated in a portable housing. Any user can thus carry with him his own nebulizing device. The device herein has at least one battery connected to the nebulizing means and the control means, whereby the user is not dependent on the presence of a mains electricity power point .

The invention is now elucidated on the basiε of an embodiment, wherein reference is made to the annexed figure which shows a partly cut-away perspective view of a preferred embodiment of the nebulizing device according to the invention.

A nebulizing device 1 is provided with a portable housing 2 in pocket format which haε on one end a detachable mouthpiece 3 which defines an outlet opening 4. Situated in housing 2 is a reservoir 5 in which is arranged a liquid, for instance an active substance such as a pharmacon or prophylactic. The actual nebulizing means 6 are arranged between reservoir 5 and outlet opening 4.

The nebulizing means 6 are formed by one or more inkjet printer elements, for instance piezoelectric or bubble-jet elements. Such printer elements are commercially available on a large scale and at low cost and have already demonstrated their accuracy and reliability in practice. The principle of the inkjet printer is assumed known so that it need not be further discussed here. The printer element distributes the active substance from the reservoir 5 in a large number of very small droplets, of which the droplet εize, which lies for inεtance in the order of 5 μm, can be precisely determined. The dispersion in the droplet εize is therefore very small, whereby the formation of excesεively large or εmall particleε, which, as stated, will generally not reach the lungs, is wholly or largely excluded. The printer element 6 is provided in the example shown with a single discharge opening 15 whereby a stream of very fine droplets 16 can be sprayed via mouthpiece 3 into the oral or nasal cavity of the user.

The printer element 6 is controlled by an electronic control 8 connected via control lineε 7 to the printer element 6. The control 8 compriεeε for inεtance a microproceεsor 9 in which the most important control functions can be included. The device 1 iε further provided with an on/off εwitch 10, while meanε 11, here in the form of a rotatable knob, connected to the control means 8 are furthermore arranged to set the droplet size for dosing by the printer head 6 subject to the nature of the active substance arranged in the reservoir 5. Two batteries 12 are accommodated in housing 2 for power supply to the control means 8 and the nebulizing means 6. In the example shown these are rechargeable, for instance nickel-cadmium batteries which, when device 1 is not in use, can be connected to a recharging apparatus, of which only a plug 14 is shown here. Although in the illustrated embodiment a portable nebulizing device 1 is shown which can be operated independently by the user, the principles of the invention can also be applied m large-scale stationary nebulizing devices such as can be found for instance m hospitals Such a device often has one or more relatively large reservoirs and a plurality of mouthpieces connected over long conduits to the reservoirs The nebulizing means can herein be arranged in the conduits or debouch therein

Although not shown here, it is possible to switch on the nebulizing meanε, which are in any caεe electronically controllable, automatically when a user inhales For this purpose a pressure sensor can then be arranged in the vicinity of the outlet opening which generates a control signal when a determined pressure occurs in the outlet opening as a result of the user inhaling When this pressure signal is generated the nebulizing means are then actuated whereby the active substance is nebulized at precisely the correct moment Depending on the placing of the nebulizing means, the control can also be set differently so that for instance the substance is nebulized at the end of exhalation or with some delay thereafter. Becauεe with the device according to the invention an active substance can be converted to a practically monodispersed spray which can reach the lungs practically in ltε entirety, the efficiency of the device is very high, whereby only a small dose of active substance has to be administered Treatment costs are hereby reduced considerably, while there is moreover lesε danger of side effects.

Although the device is described above with reference to a nebulizing device for medical applications, it will be apparent that it is not limited thereto. The device could thus for instance also be used to nebulize ink, thuε m the form of a pen or airbruεh By setting the droplet size of the ink the line thicknesε can then easily be varied herein so that such a pen would be particularly suitable for drawing. However, other applications are of course also conceivable.

Claims

1. Device for dispensing a liquid such aε for inεtance ink, a pharmacon or a prophylactic, provided with a reεervoir for the liquid, an outlet opening connected to the reservoir and nebulizing means arranged between the reservoir and the outlet opening and connected controllably to electronic control means, which meanε are adapted to distribute the substance in separate, very small droplets.

2. Device as claimed in claim 1, characterized in that the nebulizing means are adapted to distribute the substance with a precisely determined droplet size.

3. Device as claimed in claim 1 or 2, characterized in that the nebulizing means compriεe at leaεt one inkjet printer element.

4. Device as claimed in claim 3, characterized in that the printer element is a piezoelectric element.

5. Device as claimed in claim 3, characterized in that the printer element is a bubble-jet element.

6. Device as claimed in any of the foregoing claims, characterized in that the electronic control means are adapted to adjust the droplet εize.

7. Device aε claimed in any of the foregoing claims, characterized in that in the vicinity of the outlet opening are arranged pressure detecting means which are connected in signal-generating manner to the control means and the control means are adapted to switch on the nebulizing means after receiving a determined pressure signal from the pressure detecting means.

8. Device as claimed in any of the foregoing claims, characterized in that the reservoir iε exchangeable and/or refillable.

9. Device aε claimed in any of the foregoing claims, characterized in that the reservoir, the nebulizing meanε and the control means are accommodated in a portable houεing.

10. Device as claimed in any of the foregoing claims, characterized by at least one battery connected to the nebulizing means and the control means.