Surgery – Liquid medicament atomizer or sprayer – Gas stream aspirating medicament from reservoir
Reexamination Certificate
1999-03-22
2001-05-29
Lewis, Aaron J. (Department: 3761)
Surgery
Liquid medicament atomizer or sprayer
Gas stream aspirating medicament from reservoir
C128S200140, C128S202250, C128S204230
Reexamination Certificate
active
06237589
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a dispensing system, in particular one which may be of use for example in the dispensing of small quantities of medicament, where the medicament is required to be dispensed in aerosol from.
2. Brief Description of Art
It is known for dosing systems which supply a nebulized substance to containing a metering system. For example, in GB 1,568,808 (Rosenthal) there is described a metering system for supplying a nebulized substance for patient inhalation comprising a nebulizing means, a detecting means for detecting the initiation of the patient's inhalation, an adjustable timing means for adjusting a timed operation, and a valve means which is controlled by the timing means, in order to provide a controlled dosage of nebulized substance.
However, for this system to work and provide a precise dose of medicament, it is necessary that the system utilises a calibrated nebulizer which has a precise rate of output against time. Commercially available nebulizers have a wide range of outputs against time. In addition, the calibration must remain constant over the use of the nebulizer, and the nebulizer must be connected to the dosing device in such a way that the calibration of the nebulizer is valid and recognised when operated with the dispensing device. This is particularly important in relation to the length of tube between the value and the nebulizer.
Also, it is noted that this application describes no teaching of a device which is in any way calibrated for use with nominated drugs. This may have been due to the fact that the apparatus embodied in this application is designed for provocation testing, which is generally carried out in a laboratory, and is used to deliver pulses of aerosol into a patient's airway in order to determine their reactivity to allergens. The apparatus is not designed as one for a patient to take home, and to deliver precise does of medicament on a day to day basis.
In addition to the above application, GB 2,164,569 (Etela-Hameen Kauhkovammayhdiatys RY (Finland)) describes a similar system to that described above, which is also designed for provocation testing, except that it has an additional atomizing starting time control, which is used for selecting the atomizing starting moment to coincide with the beginning of the inspiration phase, which is found by examination to be favourable for a particular patient.
EP 519,742 (DeVilbiss Healthcare Inc.) describes a medical nebulizer control system which has three way valve. In the embodiment, one part of the valve is connected to a pressure sensor, and another is connected to a compressed air supply. The control system within this apparatus uses the supply tube to the nebulizer to detect the patient's breathing pattern. When it detects inhalation, it switches the valve over to the compressed air supply, which them drives the nebulizer for a predetermined period of time irrespective of whether the patient has continued to inhale or not. This device also suffers from the problems of other nebulizers in that there is a long length of tube between the control box and the nebulizer. In addition the nebulizer can be supplied from any manufacturer, and hence its calibration is not tied into the device, thereby causing variable amounts of medicament to be dispensed.
BRIEF SUMMARY OF THE INVENTION
According to the present invention, there is provided a product dispensing system comprising a calibrated nebulizer having a nebulizer jet, a mouthpiece, means for sourcing compressed air, a manifold for distributing the source of compressed air in at least one direction, a nebulizer accommodation means which is accessed by a port, and a valve means for controlling the manifold and thereby the flow of compressed air to the port, the manifold and the port being linked by a length of tube, wherein the internal volume of the tube from the manifold outlet to the nebulizer jet is less than 0.7 ml.
Preferably, the internal volume of the tube from the manifold outlet to the nebulizer jet is less than 0.5 ml.
Conveniently, the dispensing system according to the invention is utilized in conjunction with a small air compressor as the source of compressed air, which has a flow rate in the region of 1-2 litres per minute.
By “calibrated” in this instance is meant that the dosage rate for the nebulizer has already been established, and the dosimeter programmed accordingly, so as to provide a known dosage rate for a given medicament. It is envisaged that a given dosimeter will have one or more dedicated nebulizers.
In preferred embodiments of the invention, the dispensing system additionally comprises a switch means, which is responsive as to whether compressed air is flowing in the system.
It is another preferred aspect of the invention that it may comprise a dispensing system comprising a dosimeter which has been pre-programmed to dose one or more medicaments according to predetermined dosage profiles.
The dispensing system according to the invention is conveniently one which is capable of being pre-programmed to dose one or more different types of drugs, which may need to be dosed according to different profiles. Methods of pre-programming the dispensing system in such a fashion will be familiar to those skilled in the art. In addition, the nebulizer and dosimeter according to the invention are calibrated to determine the dosage of drug as described in EP 587,380 (Medic-Aid Limited), the contents of which are incorporated herein by reference.
The dispensing system according to the invention incorporates a nebulizer and a mouthpiece, by which nebulized medicament can actually be delivered to the patient. The dispensing system can also additionally preferably comprise a pressure sensor, which is capable in use of detecting a pressure drop in the apparatus in response to the patient's breathing, and then delivering a pulse of nebulized medicament into the mouthpiece. In such instances, the dose of medicament can be calculated by the known rate of output against time for the drug selected, and the sum of all nebulizer pulses which the system has delivered, in ways known to those skilled in the art, as referred to above. Such ways may typically include performing clinical trials on the drug to determine appropriate dosages, and programming these electronically into the dispensing system.
It is to be understood that the manifold in a dispensing apparatus according to the invention can, in fact, be an integral part of the valve means, and need not be a separately discreet entity. In certain embodiments, the manifold is a shaped block with internal galleys, for example, made of plastics materials, and its presence allows the tubes to be connected to the ports on the valve. The ports on the valve may be too close together to accommodate the connection of tubes directly, and a manifold increases the space between them in other embodiments it may be necessary for the manifold to distribute compressed air in at least two different directions.
The dispensing system according to the invention can operate from a variety of different compressed air sources, such as a continuous air supply at a rate of around 6 litres per minute. This can typically be provided either from a pressurized cylinder such as those used in hospitals, or can be generated from a conventional air compressor.
In an alternative and preferred configuration, the dispensing system can be operated with a lightweight compressor system, which typically generates a low flow rate (in the order of 1-2 litres per minute, preferably 1.5 litres per minute), in conjunction with an accumulator. Such a combination of low flow rate compressor and accumulator allows the dispensing system to produce pulses of compressed air to a nebulizer in dispensing system with the flow around 6 litres per minute, where the flow from the compressor is matched to the mean flow through the nebulizer (1.5 litres per minute). In addition, such a combination of low flow rate compressor with accumulator, in conjunction wit
Basista Jacek Lech
Denyer Jonathan Stanley Harold
Dyche Anthony
Lewis Aaron J.
Medic-Aid Limited
Simons William A.
Srivastava V.
Wiggin & Dana
LandOfFree
Dispensing system does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Dispensing system, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Dispensing system will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2505758