Incentive metered dose inhaler

An inhalation device for administering an aerosolized medication includes an incentive spirometer and a medication inhalation chamber having receptacle means adapted to receive a metered dose inhaler for misting aerosolized medication in the chamber. Further provided is a method for administering an aerosolized medication which involves training a subject to breath using the inhalation device and administration of the medication from the device.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
The present invention relates generally to inhalation therapy devices, and 
more particularly to an inhalation device which provides an incentive 
spirometer coupled with a metered dose inhaler (MDI) for delivering an 
aerosolized medication to the respiratory system. 
2. Description of Related Art 
The publications and other reference materials referred to herein to 
describe the background of the invention and to provide additional detail 
regarding its practice are hereby incorporated by reference. 
Individuals afflicted with diseases which compromise lung function such as 
asthma, bronchitis, emphysema, and the like are most commonly treated by 
oral or aerosolized inhaled bronchodilators. Bronchodilators, 
anti-inflammatory agents, decongestants and other such medicines are 
commonly prescribed using MDI-type devices. It has been shown that MDI is 
a superior method of aerosol administration because the small and 
uniformed size of the aerosolized medication particles more effectively 
penetrates to the smaller branches of the bronchi. 
Recent studies, have shown, however, that about 10% to 20% of patients 
taking MDI treatment fail to receive optimal aerosol deposition because 
improper or poor inhalation technique. Poor inhalation technique is 
generally due to inadequate inspirations, faulty timing, as well as 
misunderstood directions. For example, patients have difficulty using 
conventional MDI devices because they fail to precisely time the 
activation of the MDI with inhalation. Sometimes patients will inhale too 
quickly or neglect to hold their breath for a brief period of time in 
order to insure that the aerosolized medication will be sufficiently 
deposited into the airways. 
The desired time interval of breath holding time is approximately 10 
seconds, as discussed in "An Evaluation of Incentive Spirometry For 
Bronchodilator Therapy" (Frost, G., RRT., Vol. 24, Issue 5, p.11, 1988). 
It has also been proposed that a brief exhalation, followed by a slow, 
sustained inhalation will yield the most favorable results in terms of 
improved bronchodilation. Incentive spirometers, like the DHD Coach.TM. 
Model 22-4000 (DHD Medical Products Company) with a feedback device, are 
particularly useful because they train patients to inhale slowly, 
maximally, and hold the full breath. Such breath control enhances the 
patient's ability to receive optimal delivery of medication to the 
bronchial airways. 
Examples of devices using, in combination, a small volume nebulizer and an 
inhalation aid, such as a spirometer, for monitoring and measuring a 
patient's inspiration volume and airflow rate are shown in U.S. Pat. Nos. 
4,114,608, 4,259,951, 4,809,706 and 4,984,158. The devices disclosed in 
the aforesaid patents teach patients how to exercise and/or monitor his or 
her lungs while used in cooperation with a medication that can be 
inspired. However, none of these devices alleviate the difficulty of 
precisely timing manual activation of the MDI with inspiration because 
they do not allow the aerosilized medication to be held in suspension 
prior to delivery. Furthermore, these devices have the disadvantage of 
permitting large, untherapeutic droplets, rather than smaller, 
thereapeutic particles of medication to be delivered to the airways. 
Accordingly, there is a need for a device which provides a simple and 
inexpensive way to deliver an aerosolized medication, where optimal 
aerosol particle deposition and particle size is achieved, and which 
coaches the patient to achieve slow-flow inspiration and adequate breath 
holding, and which alleviates the need for precise timing of manual 
activation of an MDI with inhalation. 
Without proper delivery and deposition of aerosolized medication particles 
throughout the bronchial airways, the patient most likely will derive 
little or no benefit from this form of therapy. 
SUMMARY OF THE INVENTION 
In accordance with the present invention there is provided an inhalation 
device for respiratory care which overcomes the above-mentioned problems 
and provides a new and improved way to deliver aerosolized medication, 
such as a bronchodilator, from MDI devices. 
The device provides the advantages of coaching the patient into taking a 
slow, inspiratory flow; measurng the volume of the flow; eliminating 
large, untherapeutic particles of medication from the stream of delivery 
into the patient's airways, achieving the delivery of small particle 
aerosolized medication to the airways for therapeutic deposition thereon, 
and eliminating the problem of precise timing of inspiration with manual 
activation of the metered dose inhaler (MDI) cannister. 
The device of the present invention comprises the unique combination of an 
incentive spirometer, which is a lung volume exercising apparatus, with a 
medication inhalation chamber. In a preferred version of the invention, 
the chamber has a substantially cylindrical shape. The chamber has 
receptacle means which opens into the chamber. The receptacle means is 
adapted to receive a metered dose inhaler (MDI) cannister for misting 
aerosol medication into the medication inhalation chamber. The medication 
inhalation chamber is placed in-line with the incentive spirometer. The 
device further comprises an elongated hose having a mouthpiece downstream 
and coupling means at its upstream end for in-line connection with said 
medication inhalation chamber. 
The present invention further provides a method for administering an 
aerosolized medication to a subject. This method comprises the steps of 
providing an inhalation device, as described above, which comprises an 
incentive spirometer coupled in line with a medication inhaler chamber and 
an elongate hose having a mouthpiece. The method further involves training 
the subject with the device to achieve desired breathing parameters, 
actuating the metered dose inhaler to mist the aerosolized medication into 
the chamber, and the subject inspiring the aerosolized medication to 
achieve therapeutic deposition of the medication in the airways. 
The above discussed and many other advantages and features of the present 
invention will become readily apparent as the invention is better 
understood by reference to the following detailed description and from the 
accompanying drawings.

DETAILED DESCRIPTION OF THE INVENTION 
Referring now to the drawings, FIGS. 1-3 show an embodiment of the 
inhalation device 10 of the present invention. The device 10 includes an 
incentive spirometer 12 for indicating inhalation flow rate and total 
volume of the air inhaled, and for ensuring adequate breath holding time. 
The spirometer 12 has both an air inlet 14 and an air outlet 16. The 
incentive spirometer 12 of the present invention can be any of a variety 
of commonly available devices which provide a one-way, inspiratory airflow 
path with a predetermined flow resistance to the air passing therethrough. 
A preferable version of the invention employs the The DHD Coach.TM., Model 
DHD 22-4000, sold by DHD Medical Products. The outlet 16 includes a 
unidirectional valve device 18. The valve 18 is a conventional type of 
flat valve having a web with openings therethrough and a flexible disk 20 
which can be moved to the position shown by air flowing out of the 
spirometer 12 to permit the free flow thereof, but which closes the 
openings when air attempts to flow in the opposite direction. 
The invention may also use any of a variety of well known two-way, 
incentive flow spirometers. A one-way valve device can be fitted to the 
outlet of such two-way incentive spirometers to effectively convert it 
into a one-way inspiratory incentive spirometer for incorporation in the 
present invention. 
Outlet 16 of the spirometer is further provided with a coupling adapter 22 
for receiving in-line a medication inhalation chamber 24. In a preferred 
version of the invention, the chamber 24 has a substantially cylindrical 
shape. A substantially cylindrical medication inhalation chamber 24 used 
for this preferred version is disclosed in U.S. Pat. No. 4,938,210. For 
the purposes of the present invention, the medication inhalation chamber 
can assume other shapes which provide the chamber with sufficient volume 
in which the misted medication can be suspended prior to inspiration 
and-which cause larger drops or particles of aerosolized medication to 
"rain out." The raining out of large particles of aerosolized medication, 
as described below, results in a more therapeutic deposition of inspired 
particles. 
The chamber 24 includes a first open end 26 and a second open end 28. The 
first open end 26 is adapted to be coupled with the outlet coupling 22 of 
the spirometer 12. The second open end 28, spaced from the first open end 
26, is connected to another coupling 30, the other end of which is 
connected to the upstream end of an elongated flexible hose 32 which, 
together with the medication inhalation chamber 24 and coupling numbers 22 
and 26, defines a passage way for the flow of air toward the patient. The 
elongated hose is about 6 inches in length. 
Attached to the downstream end of the flexible hose 32 is a 
patient-engageable means 34. The patient-engageable means 34 is preferably 
a mouthpiece having a generally fan-shaped mouth piece portion. Other 
embodiments, however, of the patient-engageable means 34 may also include 
a standard face mask or any other suitable mouth piece configuration. 
The cylindrical medication inhalation chamber 24 of the present invention 
also has receptable means 36 defining an inlet port located adjacent to 
the first open end 26, and opening into the chamber 24. The receptacle 
means 36 is designed to receive a metered dose inhaler (MDI) cannister 38 
of aerosolized medicine 38 and to mist or dispense its aerosol medication 
particle contents directly into the medication inhalation chamber 24. In 
the present invention, aerosolized medication from an MDI device is the 
preferred delivery technique for reasons of dosage efficacy, reduced side 
effects and economy. 
The device of the present invention is used for the administration of 
aerosolized medications selected from the group consisting of, but not 
limited to, bronchodilators and corticosteroids. Typical bronchodilators 
administered by the device include, but are not limited to, metaproterenol 
and albuterol. A typical corticosteroid administered by the present 
invention is beclomethasone. Aerosolized medications suitable for delivery 
by the device include antifungal medications. 
Other types of medication inhalation chamber reservoirs 24 which may be 
used in the present invention include extension tubes or spacers, 
extension tube chambers with valves, or collapsible bags, as long as these 
devices provide a place for a bolus of aerosol to be held prior to 
inhalation. However, a preferred medication inhalation chamber 24 of the 
present invention is the MDI spacer device which is manufactured by 
Monaghan Medical Corporation of Plattsburgh, N.Y. As shown in FIG. 4 the 
Monaghan Aerovent.TM. spacer device 24 is comprised of a collapsible, 
cylindrical coil 40 which expands to a maximum length of approximately 
41/2 inches and is approximately 11/2 inches in diameter. The coil is 
covered circumferentially with a clear flexible airtight plastic material 
42. A first disk 44 having a centrally located opening 46 adapted to be 
coupled to the coupling 22 which is affixed to the outlet 16 of the 
spirometer 12, is securely attached to one end of the coil. This first 
disk 44 also includes a receptacle means 36 or port which is designed to 
receive the MDI container 38. A second disk 48 which also has a centrally 
located opening 50 is securely attached to the end of the coil located 
farthest from the first disk 44. The opening of the second disk 48 is 
designed to be connected to the coupling 30 which is connected to the hose 
32. The openings 46, 50 of both the first disk 44 and the second disk 48 
are coaxially aligned with each other. 
The cylindrical shape of the MDI spacer device 24 is important in order to 
obtain the optimal aerosol particle size and is also designed to hold a 
bolus of aerosol in suspension prior to inhalation. The devices 10 of the 
present invention are preferably formed from plastics which are inert and 
stable and lend themselves to processing by plastic forming techniques and 
welding. These plastic materials, when formed, provide the break 
resistance, see through, self-supporting device described and claimed 
herein. Materials and plastics which provide the desired see through 
properties may be polystyrene, styrene-acrylonitrile copolymers, rigid 
polyvinylchloride, polymers and polycarbonate polymers. 
The present invention further involves a method for administering an 
aerosolized medication to a subject. Typical aerosilized medications 
administered by this method include, but are not limited to 
bronchodilators, such as metaproterenol and albuterol, and corticosteoids, 
like beclomethasone. The method is suitable for administering any 
medication adapted for aerosilized delivery from an MDI, such as, 
antifungal medications. 
The method involves providing an inhalation device 10 for administering the 
aerosilized medication. Use of the device of the present invention, 
described above, is preferred for this method. The method involves 
training a subject or patient to breath sufficiently slowly and steadily, 
and to hold his breath for a sufficiently long period, to optimize his 
breathing control when the patient later inspires the aerosilized 
medication from the device 10. The incentive spirometer 12 of the device 
10 is the element of the device for training the breathing of the subject. 
The training conditions and breathing parameters needed for administration 
of aerosilized medications are well known (Physicians Desk Reference, 
1991, Edward R. Barnhart, publisher, Medical Economics Company, Oradell, 
N.J.) and will not be described here in detail. When the patient achieves 
the desired training parameters, the method provides for the patient to 
manually actuate the metered dose inhaler 38 to mist the aerosolized 
medication into the medication inhalation chamber 24. In accordance with 
the breathing parameters achieved with this method using the device, the 
method further involves the patient inspiring the aerosolized medication 
misted into the chamber 24 to achieve therapeutic deposition of the 
aerosilized medication in the airways. 
In using the device 10, the patient places his or her mouth over the mouth 
piece 34. The MDI dispenser 38, having already been inserted into the 
receptacle means 36, is manually actuated or activated to mist or dispense 
the aerosolized particles into the MDI spacer device, i.e. the medication 
inhalation chamber 24, in which the bolus of aerosol is held. As soon as 
the MDI aerosol has been fully dispensed into the spacer device 24, the 
patient is then instructed to inhale slowly and deeply, without nasal 
breathing, filling the lungs to the maximum extent possible on each 
breath. When the patient inspires, the flexible disk 20 of the valve 18 
allows air to flow through the spirometer 12 and through the medication 
inhalation chamber (e.g. MDI spacer device) 24, thus carrying the aerosol 
particles through the coupling 30 and through the hose 32 and mouth piece 
34 and finally into the patient's lower airways or lungs. The patient is 
instructed to hold his or her breath for up to 10 seconds in order to 
achieve optimal delivery of the aerosol to the lungs. The patient is then 
allowed to exhale by removing his or her mouth from the mouth piece 34. 
This process may be repeated as often as prescribed until the aerosolized 
bronchodilator achieves its desired therapeutic effect in which the 
bronchial tubes become unobstructed and the patient breathes easier than 
before treatment with the device of the present invention. 
The in-line combination of the incentive spirometer 12 and medication 
inhalation chamber 24 adapted for receiving metered delivery of an 
aerosolized medication from a metered dose inhaler cannister 24 provides 
the advantage of eliminating the problem of precisely timing manual 
activation of the MDI cannister 38 with inspiration. In use by the 
patient, the chamber 24 holds the misted or dispensed medication prior to 
inhalation and achieves delivery of the proper particle size. 
The substantially cylindrical medication inhalation chamber 24 combined 
with the incentive spirometer 12 provides the further advantage of 
increasing therapeutic deposition of medication to the airways by baffling 
out the larger particles of aerosolized medication. It is believed that 
large particles of aerosolized medication are less therapeutically 
effective than small particles. Respiratory Care: A Guide to Clinical 
Practice, 3rd Ed., Chapter 19, J. B. Lippincott Co., Philadelphia, Pa., 
1991. Accordingly, the invention causes the larger particles of medication 
to "rain out" against the walls of the chamber instead of being delivered 
to the patient's airways. In that way, the patient's airways receive a 
deposition of smaller, therapeutic aerosolized medication particles. Use 
of the invention thereby achieves greater therapeutic efficacy of the 
medication. Accordingly, the combination of incentive spirometer 12, 
medication inhalation chamber 24 and metered dose inhaler delivery of 
aerosolized medication further increases deposition of these small aerosol 
particles by increasing the patient's tidal volume. 
Having thus described the exemplary embodiment of the present invention, it 
should be noted by those skilled in the art that the within disclosures 
are exemplary only and have various alternatives, adoptions and 
modifications may be made within the scope of the present invention. 
Accordingly the present invention is not limited to these specific 
embodiments as illustrated herein, but is only limited by the following 
claims.